This page is a blog on building an Irish 15-foot (4.6 metre) gandelow - a small open wooden fishing boat rowed by two people and made in a traditional manner.
As this size of gandelow is very rare a prototype was built in 2012 for the Maritime Section of the Foynes Flying Boat Museum in Ireland (on the banks of the Shannon estuary). It showed that a small gandelow would be an ideal recreational boat - easy to take by trailer to a lake or a small river for family fun. In 2017 we designed and built the version below.
A 15-foot (4.5 metre) long Irish gandelow fishing boat.
You can download basic plans here (PDF). They contain diagrams and dimensions in Imperial, ie inches and feet, and metric sizes. Later, detailed plans (not instructions) for a 16-foot (4.8 metre) gandelow will be published in 2019. If you want some guidance on general boat-building techniques then go to sites such as WoodenBoat publications.
The posts below record the building process and are in date order (most recent first). In this blog we refer to ‘Step 1’, Step 2’, Task 2-2 etc. These are from the book ‘Building a River Shannon Gandelow: Step-by-Step Guide with Plans’ published in 2015. For reference, the full list of steps are in this PDF.
To contribute to this blog - please email your comments to me and I will include them (if appropriate).
Links to posts by month: 2019: January. 2018: June. 2017: November, October, September, August, July, June, May, April, March, February, January.
Links to other topics discussed below: Douarnenez French boat Festival 2016, Glandore Irish boat festival 2017,
I am thrilled to announce that my article on the Shannon Gandelows has been published (in French) by the magazine ‘Chasse-Marée’ based in Douarnenez, Brittany. Chasse-Marée publishes articles about the culture and techniques surrounding traditional boat building and its archives and museum have a high standing among the boat-building community. Many excellent reference books are available from their shop. Every two years (the next is in 2020), Douanenez hosts a spectacular in July festival called ‘Temps Fête’. If you are in the area I highly recommend you put time aside to visit. It’s not just about boats! Music, dance, food and a vibrant social scene make it unforgettable.
May I take this opportunity to thank everyone who has read and commented on this blog and I wish to give a big thanks to all those who have supported the project along the way!
A few of bits of news to finish off this blog. In Watercraft Magazine’s July / August edition (W130) they have published an article based on this blog - specifically focusing on the design and build issues involved in scaling down to a 15-foot gandelow (4.6 metres) from 23-foot (7 metres) one.
Also, in spring 2019, the French boat building magazine ‘Chasse-Marée’ will publish two articles about the gandelow (in French). The first will look at the historical, cultural and societal impacts of the gandelow on the life of the people of the Shannon estuary in western Ireland (where the boat was used for fishing); the second will compare and contrast the Irish boat building techniques with the French ones. These will be very special editions as their artwork is fantastic!
Lastly, in case you missed it, the ship ‘A K ILEN’ was launched in June and is now being fitted out, ready for its return to the City of Limerick in September 2018. A fantastic achievement - I have been proud to assist in a small way. She certainly looks very special (photo credit: Kevin O’Farrell). More on the story here on twitter, and at the Ilen Boat School here.
In the workshop Christmas presents are being made and, as the frosts have arrived, there will be little activity now till after New Year - probably not till February. So I wish you all the best for the Festive Season and good wishes for 2018!
Oh! One thing. Wooden Boat magazine asked me about my gandelow item in their ‘Launchings’ column - they asked “Have I built both 15 and 16-foot gandelows?”. The answer is no. The boat that was launched (and featured here) is 15-foot 10 inches long (4.75 metres). So sometimes I round it up and call it a 16-foot boat, sometimes round it down and call it ‘15-foot’. Apologies for any confusion! Anyway, Figure 48 shows the finished boat with the author rowing and Christine the ‘gunwale fitting assistant’ looking more calm than she was on that difficult day!
Figure 48 - Rowing the finished boat on Staunton Lake, Gloucestershire, UK (Photo: D J Marsay).
This post covers some of the final steps involved in building the 15-foot gandelow - plus some ‘lessons identified’ of things to do better next time. I’m going to pick up the story from the May 2017 post below, where the sheer planks had just been fitted and will only mention items that are significantly different from the 23-foot boat.
First, lets go back to Step 6, fitting the ribs (knees). The 23-foot gandelows have nine ribs and a smaller one would usually have seven. However, when I was doing the scaling down it was far easier to stay with nine ribs. I felt that to re-work all the in between rib dimensions for seven ribs was beyond my skill. Nevertheless, the end result is a much stronger (and slightly) heavier boat. The verdict from the boat builders in Limerick was positive, which is good!
One consequence is that fitting ribs 1 and 9 to the planks is a little harder than for the bigger boats, for two reasons: a) you are working in a tighter corner, and b) the bevel angles are more extreme (as Figure 47 shows).
Figure 47 Fitting the ribs at Station 9.
In May I had unwisely agreed to a (somewhat arbitrary) launch date in June and so the pressure was on ... As a result I started taking shortcuts and altering the build order. The first change was to turn the boat over before all the ribs were done (only 3, 4, 5, 6 and 7 had been finished). This was so the caulking and bottom painting (Step 9) had time to dry - as there was a suitable long weekend coming up and it seemed too good an opportunity to miss.
How was I going to turn it over at short notice? My crew of ad-hoc helpers were not around and it had to be done. Aha! The ring bolts! They are in the stem and stern post and each can support a ton each - with ropes and pulleys I lifted the boat in the air and (with more than a bit of anxiety) flipped it over (see Figure 46). Nothing broke, but the bracing I had put across the sheer was not quite strong enough and the shape of the boat altered slightly - maybe for the better?
Figure 46 - Turning the gandelow over, single-handed style.
Anyway, the caulking and painting was then done and after the holiday the boat was turned back over again, the rest of the ribs fitted and the aluminium primer and grey undercoat finished. BUT! Then, the real horror turned out to be Step 7, fitting the gunwales - lots of lessons here! The first being - get the best quality wood that you can ... I was using some of my Douglas Fir, but not my best pieces and there was no time to source better stuff (oh how I came to regret that launch deadline!). The gunwale has to curve, twist and bend upwards - it puts huge stress on the wood. Afterwards, in Ireland, I was told with a knowing smile that many boat builders put naturally twisty pieces of wood on one side for gunwales. Bother, I had had some of that but had sawn it up as ‘useless’ - another lesson!
Confidently I went ahead with the procedures we used in 2014 ... oops, first error, forgetting to reduce the gunwale measurements for the smaller boat. The 2” wide size was too rigid for the smaller boat as the curves, especially at the ‘shoulder’ (the front quarters), are tight. But we were already steaming, so push on ... guess what? The wood started to split like matchsticks. We clamped the damaged gunwales in place (Figures 44 and 45, note the clamp supporting the sheer plank at the transom) and, when dry applied ‘Tite-Bond’ wood glue to the damaged area, clamped it in the curved position and left it overnight to dry.
Figure 45 - The gunwale clamped to the outside of the sheer plank, stern view.
Another lesson here. In Figure 44 the port gunwale extends beyond the stem head, this is the correct way to do it so that it can be pulled round into a curve (there is always a straight bit near the end that can’t be bent). The starboard gunwale is too short and, guess what, is too straight!
Figure 44 - The gunwale clamped to the outside of the sheer plank, view at bow.
Next morning, hurrah, it worked! So we went on to fit the gunwale inside the sheer. First we attached supports at the stem and transom (Figure 43) and then worked the gunwale in, clamping both to the sheer plank and pushing down onto the top of the ribs as we went. It was a truly nasty experience, and thanks go to Christine for dealing with it so calmly - the physical stress and tension are pretty unpleasant. Anyway, it worked in the end without further mishap (Figure 42). Even the task of scribing the rear of the gunwale where it meets the transom went well. The trick here was to to scribe and fit a short section of gunwale to the transom and then transfer the measurements from it to the real gunwale.
Figure 43 - Sheer plank supports at stem and stern (note sturdy transom brace).
Figure 42 - Port gunwale after fitting inside the sheer plank, starboard one still outside.
After this, finishing the rest of the gandelow was relatively easy. The remaining parts of Step 8 was completed. That included: fitting the stringers, shaping and positioning the thwarts (they have to go round the ribs), and making and fitting locker lids for the bow and stern. I started by positioning the thwarts the same distance back from the stem head as for the 23-foot gandelow, but they were too near the stern. I sat in the boat and, simulating rowing with the oars, tested various positions. A number of factors have to be considered, such as: where are rowers feet relative to the saddles; will the ribs get in the way of fixing the thole pins / pads to the gunwale; and will the weight of two rowers balance the boat?
Unfortunately, the position I chose for the front rower turned out to be about 9 inches too far back, and the distance between the rowers thwarts (at 30”) slightly too narrow. Instead, you should put the front thwart so that its forward edge is 63 inches back from the stem head and put the thwarts at least 32 inches apart. However, don’t fix anything in place till you have tested the thole pad / thole pin hole positions on the gunwale relative to the thwarts - you can move things an inch or two each way to avoid hitting nails, ribs etc.
Also in Step 8 is making up, shaping and vanishing the rubbing rails and fitting them to the outside. I used mahogany (as the Utile I had bought had shakes in it - oh for good quality wood!) and screwed the rails in position - filling the countersunk holes and varnishing over the top with Rustins yacht varnish. As Figure 41 shows it looks smart!
Figure 41 - View of the finished rubbing rails and brass nameplate (Photo: H Ludwig).
In Step 10 a pad was fitted on the transom to hold a long-shaft outboard (Figure 40, the angle is not yet adjusted) and for a mast so that I could try simple downwind sailing (Figure 39). The final modifications and tests took place in July when I was in Ireland - with all the fun of rowing, sailing and motoring the gandelow that went with it (videos here).
Figure 40 - Testing the angle of the outboard motor pad (the motor setting still needs to be changed).
Figure 39 - Modifications to add a rudimentary rigging.
There‘s no discussion about the gandelow in this combined August and September post (on holiday and busy with non-boat tasks). However, my ‘Tideway’ 12-foot sailing dinghy needed a bit of TLC (I purchased the boat second-hand in 2014 to sail on my local rivers, the Avon and the Severn in the UK). Last year, see Figure 38, she was part of the Douarnenez ‘Temps-Fete’ boat Festival in Brittany, western France. And in 2015 she was sailing off the coast of Ireland. In all cases the boat leaked more than I though appropriate. So I decided this year to turn the boat over and investigate.
Figure 38 - The Tideway-style sailing dinghy ‘Swan’ in Douarnenez’s harbour, France, in 2016.
The reason for the leak turned out to be a faulty plank lap in the turn of the bilge - plus some of the laps on the other planks had not been correctly bevelled. Somewhat reluctantly, on such a classic little ‘Swallows and Amazons’ boat, I decided that some careful epoxy filleting was required.
Figure 37 - The underside of Swan after adding epoxy fillets (2017).
I started by removing loose putty filler at the laps with a triangular scraper and then the various layers of paint with a heat gun. I found that some of the copper fixings needed attention too before I filleted with epoxy. I then sanded, sealed, undercoated and applied a top coat in blue. In Figure 37 the white edging is yet to be painted, but the end result is good. The boat is now stronger and I’m sure it won’t leak (!). This is not a class-compliant Tideway so I have been tinkering with the rigging (mainly so there is a little more room under the boom). I have also added some weight to the centreboard and dealt with a leak where the centreboard case meets the keel. Now that it’s all done I hope to squeeze in a quick sail on one of the English lakes before the winter sets in to find out how much the adjustments change the boat’s behaviour.
During July I was at the Glandore Boat Festival in south-west Ireland. I moored the boat on the sea in ‘Blind Harbour’ for three weeks. There is an article about the festival in the online magazine ‘Afloat.ie’, which includes a photograph of this gandelow at its launch ceremony.
For the Glandore ‘Parade of Sail, I tried the 15-foot gandelow with a simple baggy-footed sail (the jib off another boat) attached to a temporary mast. Some of the festival-goers thought that the boat would be too unstable (as it has no keel or centreboard), but it went well downwind and could be steered 30 degrees or so either side of that (with the oar over the stern in the old style). The thole pins double up as belaying pins, so no extra equipment is needed. The Shannon fishermen would have used an oar for the mast and an old tarpaulin, or linen flour sacks sewn together, as the sails.
Figure 36 - Sailing the gandelow ‘Swansong’ in Glandore harbour, south-west Ireland (Photo: Gary MacMahon).
I also tried a 2.5HP outboard on the boat and was very pleased at how fast it went - even over slightly choppy sea (see the videos here to get an idea of how stable the boat is). I wonder if the ‘gars’ along the underside edge of the boat create a bubble effect which reduces friction (as discussed in this article)?
Figure 35 - Staff at the A K Ilen School, Jim (left) and Liam, receiving the gandelow as a gift from the author (right).
At the end of the trip I took the gandelow to Limerick and donated it to the A K Ilen School and Network for Wooden Boat Building. It will be used as a template by the students who might want to build a similar boat. At the School, local gandelow builder ‘Sparrow’ gave it the once-over and pronounced that it was ‘about right’. Apparently the garboard is slightly too narrow between stations 7 and 4. I was then lucky enough to be taken to the iconic Curraghgour Boat Club (1000 years old), plied with tea and admitted to the secrets of the proportions of a real gandelow. I was also shown a map of the Limerick fishing guilds and the parts of the Shannon river where they fished (an article on this next year).
Whilst taking the gandelow around the Irish backroads my trailer suffered near-catastrophic metal fatigue. Thanks go to to Liam of Hegarty’s boatyard and to Nick who did the welding. Without their generosity I could never have taken the boat to the A K Ilen School in Limerick. Why did the trailer fail? Well, as Figure 34 shows, there are two reasons. 1) The gandelow was really too long for it and so undue weight was put on the overhang at the back, and 2) the launch trolley puts all the weight on the rollers to the rear of wheels (this has now been corrected). Ok, there’s a third reason, some of the back roads are very uneven so there was a lot of bouncing about which didn’t help. The failure occurred (both sides) where the angle-iron side pieces met the main cross-beam - I was lucky not to lose the boat, trailer and car. And yes, from this angle, it looks waaayyyy too long! In my defence, I did balance out the weight on the tow ball correctly.
Figures 34a and 34b - Showing the point where the trailer cracked, and the repaired / strengthened version below.
Figure 34b - The trailer after repainting (with Hammerite).
Thanks go to the blacksmiths (Christopher and Chris) on the Industrial Estate for their advice and practical assistance in making the repairs (after all I am not a metalworker!). The other change I have made is to alter the launching trolley such that it: a) supports the keel of the boat better and, b) puts the main weight of the boat on the central (strengthened) cross piece. The mudguards have also been repositioned and properly supported (strong enough to stand on now).
The gandelow was launched on Saturday the 24th June at Staunton Court lake - the first of its type to be built anywhere! A gathering of friends and onlookers watched as a traditional naming ceremony was carried out and the boat was launched. It took to the water beautifully and turns out to be easy to row. Guests were taken around the lake in the boat and a small celebration lunch was enjoyed. Here a just a few photos to start with.
The first shows the gandelow ready for the launch - note the oak leaves on the bow. The legend is that this is so the boat doesn’t forget to return to land (where the oak comes from). The posters in the background are about the A K Ilen School (whose work inspired the author to build a gandelow). The second photo shows the boat on the water (with the author rowing). And the third shows the boat completely fitted out with lockers (which will have buoyancy bags in).
Figure 33 - The gandelow with a display of posters from the Ilen School (Limerick).
Figure 32 - The gandelow after launching with the author rowing and a test passenger ... Achim B.
Figure 31 - The finished 15-foot gandelow with oars and locker lids in place - ready for Ireland!
In July the boat goes to Ireland to take part in the Glandore Boat festival. So the August post will have some photos and film from that. The rest of the post will detail all the rest of Steps of building the gandelow (not mentioned so far). Plus there’s a lot of things that have been learned along the way that I’d like to mention.
This months post is a short one with more detail to follow in June. I have now finished the sheer planking (Step 5) and started on the internal ribs (Step 6). Plus there has been time spent on cutting and shaping timber ready for the final Steps of the build. The oars have been turned on the lathe and planed to their final shape, varnished and the bottom edge epoxied for strength (Step 8). The ‘A-frames’ have been removed so it really is looking very good as you can see.
Figure 30 - The sheer plank screwed in place at the bow and fully nailed.
Figure 29 - The sheer plank screwed in place at the stern.
There’ll be much more detail about all the things that have worked well (and that have been a challenge) after the boat launch in June. One of the main difficulties so far is the wood drying out fast - we have had temperatures up to 30 degrees Centrigrade (85 Farenheight) in the workshop. But no serious cracks!
Hi! Lots to talk about this month. The main challenge has been shaping and fitting the first butterfly plank. I’ll describe how that was done (after I’d fitted the garboard and gorings). Also, the four oars (paddles) have been made and shaped roughly - they need to be turned and finished off next month.
Next month’s posts will also be about fitting out the ribs (frames), adding the quarter knees and the gunwale. Let’s see how it goes. If there’s time, I’m going to make a simple ketch rig with sprit sails or standing lugsails for the boat in June.
Please note the launch date - Sunday the 25th June at 1100 - I’ll confirm exactly where (in the UK) next month. Then it’s off to Ireland in July (with the gandelow) to take part in the Glandore Regatta and boat festival.
Step 3, Task 3-5 and 3-6 - Shaping and fitting the garboard and gorings. These tasks went quite well - other than I found I needed much wider stock (10”, 25cm) than I originally thought. I used 8” (20cm) wide Scots Pine and when I cut the bottom curve out of the wood, I just turned it over and clamped and glued it as a fillet on the top to provide the extra width. I then used a thicknesser to get the planks to 5/8“ (16mm) thick, meaning the glue line was almost invisible. Then the top curve of the plank was hand planed to match the template that was scribed in March 2017 post. I carefully shaped and fitted the hood of the plank at the stem before steaming. I made some clamp supports, shown in the photo below, to help pull the plank into shape without slipping off the stem.
Figure 28 - Fitting the hood of the garboard showing the clamp supports.
I had to protect the glued joint from heat while I was steaming the front quarter of the plank, and then at the stern also. As the fillet was mostly at the centre there was no problem (though I temporarily put a couple to screws vertically down the thickness of the plank just to be sure). Once the garboard was steamed and clamped I then used galvanised nails to fix it into the floor (back to station 7) as described in the Plans book - cutting the rear end to the stem post last. Finally, stainless steel screws were used to fasten the hood and stern, being careful not to drive them through the plank! The gorings were cut from plank offcuts and fitted to the top of the garboard at the stern.
Step 4 - The first butterfly plank. Again, wider stock than I had expected was required - so, off to my local timber supplier, Handyman House in Tewkesbury. Unusually for England now, they are happy for me to sort through their planed timber to pick out the best pieces. I scribed the plank onto 3/8” (10mm) rough plywood and adjusted it till it sat well on the frames. Then I used tick sticks (as described in the Plans book) to measure the rolling bevel every 3” (7.5cm) from the transom forward to just beyond Station 7 (the measurements are on page 16 of the updated 15-foot gandelow plans).
When I was happy with the fit of the scribing board, I started to transfer it to the stock and **!!**!!!t - I had cut one of the pieces of timber just, no almost too short - idiot! However, the other was fine, so I cut it out, marked out the rolling bevel and planed it to shape and went ahead and steamed the plank and fitted it. And, as you can see below, it fits! The twist of 50 degrees occurs over barely 20” (50cm) so I made a simple tool that my assistant could use to control the twist.
Figure 27 - First butterfly plank after steaming, with the tool used to help twist the plank.
I’m priming the plank overlaps with aluminium primer paint before fitting and then using a mastic in the joints that remains flexible. The laps are then fastened with galvanised nails.
Step 4, Task 4-5, The second butterfly plank. I’m using the scribing board from the first butterfly plank to capture the offsets measurements for the top of the second plank. Then, to get the lap, I just draw along the top of the first plank onto the inside of the board (using a different coloured pen so the markings don’t all get mixed up!). I’ll then lay this on the stock and transfer the offsets to it and cut the plank to shape before final fitting. The photo below shows clearly the garboard and first butteryfly plank after nailing (yes I did use ‘goop’ - a technical procedure ;-). I’m not happy with the line of the overlap, especially in the centre part of the boat - it will be better on the next one. Note that the bottom of the garboard is supposed to be ragged at this stage as it will be faired off when the boat is turned upside down.
Figure 26 - Scribing the second butterfly plank.
Step 8, Task 8-4, make the oars (paddles). The four oars are each 8’6” long and also made out of laminated Scots pine. The dimensions and shape are fairly standard as you can see - these are just the rough blanks so far.
Figure 25 - The oar blanks ready for shaping.
STOP Press No 3 (updated 24 April). Plans for the 15-foot gandelow are published - you can download them (free!) by clicking on this link. The plans (in a 4MB PDF, scaled to be printed on US Ledger or European A3 pager) containing 16 pages with:
Other news: The weather has really warmed up nicely so I’ve started shaping and fitting the planks. The garboard (lowest plank, Task 3-4 of Step 3) template I have scribed and shaped (see the view from the stern below). It looks similar to the one in the model - which is reassuring! Here’s a TIP - use different colours of roller ball / biro pens for each of the plank markings - that way if you re-use a scribing board you won’t get the measurements mixed up!
More to follow next month - hopefully it will be beginning to really look like a boat!
Figure 24 - The trial fit of the garboard template.
This has been another ‘out of the cold’ month and so the boat modelling has progressed. I’ve also just about completed the drawings of the boat frames (molds) which will be published in a FREE PDF next month. I used the Visio drawing package to make the diagrams (as I did in the Building a River Shannon Gandelow: Step-by-Step Guide with Plans book), which is great once you get the hang of it, as it keeps everything to scale.
Having now faired the dimensions properly, the DelftShip software produces a model showing how it thinks the shapes of the planks (strakes) - I’ve shown an example below. A full set of all these drawings will be in next month’s PDF.
Figure 23 - The gandelow’s planks - exploded view.
I had two things which are not right on my prototype of the 15-foot gandelow (corrected in the diagrams to be published of course). One was that I had made the rabbet angle on the stem and stern too shallow (where the end of the plank fits into the posts). It means I’ve had to add some fillets of wood to correct it. The second issue was using some old epoxy resin that I had as a filler. BIG mistake! It didn’t go off so I had goo the consistency of marzipan to remove - I hope the new filler isn’t affected by what has soaked into the wood. A perfect example of one thing leading to another. Doh! The rest of the month has been taken up with planing some of my stock to thickness, and making some simple wooden cam clamps and ‘gripes’ and a lofting table (see photo below - it’s 21-foot, 6.3m, long and 4-foot, 1.2m, wide. It can be unclipped from the wall and stood on trestles).
Figure 22 - The completed lofting table.
I’ve also been studying the plans of Robert H Baker’s ‘Piccolo’ which I’m intending to build for my cousin (it’s a very delicate double-ended sailing canoe). It features in Wooden Boat Magazine numbers WB36 and 37 (see the study plans here to get an idea what it looks like). I’ll have to loft it, that’s why I made the table. Building the boat may be beyond my skill (the planks are only quarter of an inch, 6mm, thick for a start) and I’m not sure I can source the fine quality of wood he used. Anyone got a load of Huorn pine going cheaply?!
Stop Press No 2! The list of correction for our gandelow books has been updated (PDF, 55kb) - adding new data to Table 7. Also, in case you missed it, the Table of Dimensions for the gandelow was updated. Please re-download them to get the new versions (they have the same name, but have a version note in the title).
What with end of year religious and consumer holidays and 2017 arriving without too much trouble and the weather being often below freezing work in the workshop has been largely on hold. Despite that, work has gone on building the molds / frames and fastening them to the floor of the gandelow.
The BIG excitement has been successfully transferring the dimensions into a freeware boat modelling tool called ‘DelftShip’ (there are several of these tools to choose from, see this page for examples). I chose Delftship because it was used at the Lyme Regis Boat-building academy where I did some courses in 2012. You can download Delftship v8 here - also download the Version 8 manual that goes with it!
Figure 21 - 3D view highlighting the top-of-plank lines - a bit uneven at this stage!
As you can see, it produces a model that even looks like a gandelow - a golden one! More detail still needs to be added (such as to correct the transom shape and add the stem and stern posts). The point of the model is to do some basic cross-checking of dimensions; plus the software can assess sea-worthiness, stability and so on - though there is obviously no substitute for putting a real boat in the water!
So, how can you have a go at this yourself? Firstly, download and install Delftship (if you get an OpenGL error, then email me and I’ll let you know the fix). Next, start the software and go directly to the leftmost tab, select ‘Preferences’ and in the ‘General’ tab unclick the “Reopen last project on startup” box (I got confused with projects opening on top of each other, this tip stops that). Then click the green tickmark to save the preferences.
Now you are ready to load the dimensions. DelftShip is a technical tool and rather quirky to use. I found out by trial and error that its defaults are set for round-bilge boats of carvel (planks edge to edge) construction. Wheareas the gandelow is clinker-built (lapstrake). DelftShip deals with that by letting you import a file of ‘chine’ data that defines the centreline, edge of floor and top-of-plank measurements. You can download the one I used (to make the model above) which is in this simple text file - it has comments in it: Gandelow-15-foot_Delftship_Chine-data.txt - save it to your computer.
In DelftShip, go to the ‘Home’ tab, click on ’Project Settings’ and select the units to be “Imperial”. Now click on ‘OK’ to save that setting. Next, click on the little black down-arrow next to the yellow folder symbol (see screenshot below), select ‘Import’ and select the ‘Chines’ option (it took me some time to find this import function!). Use the dialog box to navigate to where you saved the chine data text file, select it and click on ‘Open’. The software will ask you ‘Number of points on each chine’, check that it says 11, and then click ‘OK’. You should (!) see half a gandelow ... To make it a whole gandelow, click on the ‘Tools’ tab, look for the ‘Transform’ tools and click on ‘Mirror’. Click ‘OK’ twice to select the defaults. Your project ought now to look like the one above.
Figure 20 - Delftship’s view options.
When I have a better model (the current one has what are known, not at all reassuringly, ‘leak points) I will upload it. Even this basic model shows that the centre-of-gravity and centre-of-buoyancy are about right, which is good. Here’s some other things to try: On the Tools tab, in the ‘Project tools’ area, click on ‘Lines Plan’ and you get side, plan and stem and stern projections as below - neat eh! From now on, experimenting is up to you - play and have fun. ;-)
Figure 19 - The 3D views generated by the Delftship software.
The end of the first year in the workshop has arrived - where did the time go? Not that much seems to have been achieved but when you compare the workshop now to how it was in April a lot has been done ...
I have been asked a question about the bevels on the edge of the floor (which is why I updated the corrections to the books) - “Why aren’t the floor bevels by the stem and stern post nearly vertical? Surely the planks are almost upright at this point?”. A good question and one which had worried me when I was producing the first version of the Table of Dimensions. The answer is the sort of thing that naval architects and boat designers work with - so if the following detail is not for you then please skip on to Part 1 of the December 2016 blog.
The answer is best given with some examples. Suppose we are going to make a wooden box with sides that slope out at 45-degrees from the floor (as in Figure 17, Diagram 1 below). That’s easy - the bevel on the side of the floor is 45-degrees all the way along - we set a bevel-gauge to that and measure from the top of the floor to the bevel as we plane.
Now a gandelow has a floor that is dished across the top - this is the first complication - that the the floor is not flat and horizontal. So we need the angle between the top of the (concave) floor and the sides. Diagram 2 shows how it is worked out - the drawing is an extreme version so it is easier to see the angles.
Figure 18 - Diagrams showing the effect on the side bevel of a curving floor.
The next complication is that the gandelow floor narrows towards the front and the back - and the curve of the top of the floor is less there (see Figure 14). So, even if the sides of the boat were to be 45-degrees all the way along, the bevel angles, relative to the top surface of the floor would change as we moved towards the centre of the boat. For example, if the floor curved up 10-degrees in the centre then the side bevel would be 35-degrees. If the curve is only 2-degrees by Station 1, then the side bevel would be 43-degrees. Yes, my brain is beginning to hurt too!
OK. Almost the last complication now. The bevel is always measured at right angles to the edge of the floor at you look at it from above. Well, you say, why would that make a difference? Try this ... if you use a bevel gauge to measure the floor bevel at right angles to the curve of the floor edge, and then turn it to be in line with the station line, you will see the angle change - try several times if you are not sure. Generally, the bevel angle appears to get smaller as you turn the gauge away from being at right angles to the edge.
Figure 17 - Showing how the bevel angle is measured at right-angle to the curve at the edge of the floor.
So! All these variations are factored into the dimensions and angles in Table 7 of the books. But, I hear you say, you still haven’t explained why the bevel angle isn’t 90-degrees at the stem and the stern? Take a look at the photo in Figure 16. The stern post is not vertical - it slopes backwards. As you can see the first side plank, the garboard, therefore has to slope outwards to meet it. If the stern post was vertical then the garboard could be vertical. Again you can try this with some pieces of wood to see how the angles change as the stern post slopes at different angles.
Figure 16 - Illustrating how the slope of the stem post affects the side bevel angle.
If you have got this far then well done! Of course, none of this really matters to us - we have some measurements which have come from centuries of people building gandelows. If we follow their lead then all will be well - but sometimes it’s interesting to think about how, as these shapes and angles change, the shape and seaworthiness of the boat changes with them. That’s something that master boat-builders and shipwrights understand - all power to them!
Stop Press! The table of dimensions that was issued in October has been updated - please re-download it to get the new version (it has the same name, but has an update note on the first page).
Amazingly, the floor is made (that’s Task 1-2 and 1-3 of Step 1) and fixed it to the strongback! There’s a few things that I changed from the description in the Gandelow Plans book. They are:
The first photo pair below shows the saddles after their undersides were shaped in a gentle curve and the nailing from the underside. The second shows the finished job on the strongback. I have not yet painted the whole floor as I need to see the Station positions and Centreline marks for when I fix on the molds / frames.
Figure 15 - Showing the way that the floor is nailed to the saddles.
Figure 14 - The completed floor showing the variation in the curve of the top surface.
Building has started (at last) and the office and mini kitchen in workshop are finished so with temperature falling towards freezing there with be somewhere warm(ish) to go and make a hot drink.
Step 2 is where we are now - making the stem and stern posts, shaping the transom and gluing the stern post to the transom together - as the photos show. These parts have all been made of a wood called ‘utile’. For the stem and stern posts I have ‘cheated’ in that I have cut the stock down the back rabbet line, shaped the rabbet bevels and then glued the halves back together (see Task 2-1 in the book).
The bevels on the edge of the transom are fiendishly tricky - lots of concentration and double checking required. The bevel angles are always taken at right angles to an edge (on the tangent on the curves). Remember that the angles on the plans in the book are for the 23-foot gandelow - I’ll give the ones for the 15-foot version when I have checked them!
Figure 13 - Gluing the stem and stern posts and transom.
It feels very good to be properly underway with building the boat after so much time, but then a lot has happened. Next job this month will be Task 1-2 and 1-3 of Step 1, making the floor and fixing it to the strongback. Hopefully I’ll be well on the way to putting all these parts together as December starts ...
October has arrived! After much delay the gandelow building will start (honestly). First off, I have to finish making the frames (molds) which will determine the shape of the boat. Drawings of the final versions of the frames will be in the plans book. Then I’ll go on to build the boat’s floor and bevel the edges. If there’s time this month I’ll also start on the stem and stern post and transom. An ambitious programme ... ?
OK, so it didn’t quite work out as planned! A minor arm injury slowed me up, but I have now got the ‘lines’ of the boat for you. Click on the table image below, or right-click on this link, to download a PDF of the dimensions of the boat. It’s not a ‘table off offsets’ (that you might get from naval plans), but the half-breadth, full-breadth and top-of-plank sizes that can be used to build the floor and the frames (molds) which shape the boat. The measurements come from the ‘3D lofting’ with battens representing the planks. I think it looks good (see the photo below). At least, when people come past the workshop they say ‘that looks a lovely boat’ - which is good that a) it looks like a boat to them, and b) that they come in to look closer.
Figure 12 - Table of dimensions for the 15-foot gandelow [Updated 12 December 2016].
Figure 11 - The 3D lofting complete.
More Gandelow Builders - Stories from around the World. I was contacted by Greg from New South Wales Australia. He was on a tour round Europe and went to Ireland as his ancestors come from there. He visited Limerick, and the Ilen School and saw the currachs and gandelows there. As a result he sent me his family story. Here’s some parts of it:
By now I should’ve started building the boat - but a few things have come along to change the order of things. Firstly, with autumn (fall) on the way, we need a place to make tea, cook the occasional snack and to warm up when the weather gets cold. So making a combined office / kitchen has become a priority. A wood-burning stove would make sense too, but it’s not allowed (as the barn is a very old protected building with a wooden roof). Pity
Also, the opportunity came along to help finish decking out the ‘Ilen’, a 56-foot wooden boat I have mentioned before. So, off to Hegarty’s Boatyard in south-west Ireland with my small sailing boat in tow. It’s always worth visiting there as there is much of interest to see every time (such as small wooden boat renovations, trawler refits and so on). But the main focus is the Ilen renovation. Here are a couple of photos showing the deck before and after decking. The deck planks are of Douglas Fir, about 2 inches (5cm) thick and about 3 inches (7.5cm) wide fixed with ‘cut’ galvanised nails. The three photos below show the nearly finished result; the deck beams readied for planking and a view of the ‘joggling’ where the nose of the planks meet the larch cover boards at the sides; and lastly a close up of the tip of the plank and of the gaps left between the planks for caulking and where the nail hole plugs will go. The deck is going to be painted.
Figure 10 - The decking complete and the bowsprit and port side stanchions in place.
Figure 9 - Views of the Ilen’s deck beams and the decking underway.
Figure 8 - Details of the butt joints and ‘joggling’ at the ends of the planks.
So, the ‘3D lofting’ is under way. What do I mean by that? Well, the dimensions I have are for the length, depth and width of the boat at various stations and at top of planks and sheer at stem, stern and transom. These are not the usual waterlines or ‘buttock lines’ you find in a table of offsets. I could produce such a thing but have decided that the best way to fair the lines is to build a skeleton boat - which I have done (as the photos below show).
I started with Step 1, Task 1-1 (making the strongback) and then built on that. The left-hand photo is the bare skeleton; the right-hand one shows the 3D version with the first test frames / molds from overhead. Not bad, but still some work to do! I’ll provide all the faired measurements and more photos in a downloadable form later this month [now delayed till October owing to going to Ireland to do some serious boat-building].
Figure 7 - 3D lofting the sheer and the floor bevel.
For information, some of the design criteria that I considered for the 15-foot gandelow are that:
The 15-foot Foynes gandelow-dory hybrid (that I started with, sketch plans below) has proved to be unsuitable to use, on its own, as the basis for a gandelow proper. So I have had to develop a shortened version of the 23-foot gandelow. The draft measurements look OK, but they’ll need some ‘3D lofting’ to check them out. Next month’s job!
The rest of July has mostly been taken up with preparing for and taking part in the Douarnenez ‘Temps Fête’ boat festival in Brittany (France). It is spectacular! Six days of events at sea and ashore - from 18th Century frigates in full sail firing cannon to tiny traditional boats weaving in between - with music, good food and joie de vivre! There are boats being built and launched, ropes being made and every other maritime craft represented. It is a down to earth festival for and by maritime people - all about craft and fun. I took part and joined in with my 12-foot ‘Tideway’ sailing dinghy.
The best photos and videos are on the Temps Fête Facbook page, but here are a couple of mine. The first is of a replica caravelle (it is one where you can book a place to work as crew for a day). The second is a French fishing boat (a ‘canot’) waiting for launching. It was constructed by the boat school in Douarnenez (Les Ateliers de l'Enfer).
Figure 6 - Reconstruction of a pirate caravelle.
Figure 5 - A French fishing boat, ‘canot’, built by the Ateliers de L’Enfer (literally, the ‘Workshop of Hell’!).
Timber has now, finally, arrived. It’s great to get the smell of new wood into the workshop which has had too much of new paint till now! Sourcing suitable material is not easy in the UK where good wood is very expensive and alternatives (not always ideal) have to be used. Also, there are now very few timber yards where you can go, point at a piece of wood and say “That one please”. Timber supply is now optimised for CnC / engineered products and humble craftsfolk are too small a market to bother with. I gather that it is very different in North America (and in mainland Europe where quality timber is widely available, eg in France, Germany and Scandinavia). More on this next month.
Adapting the Foynes Gandelow. As I mentioned in April, a 15-foot ‘experimental’ gandelow-dory hybrid (with a ‘tombstone’ transom) was built for the Foynes Flying Boat Museum in Ireland (it was never intended to be on the water). I have brought together the rough dimensions for this type with a few sketches and photos in this PDF [1.5MB]. Progress is being made in adapting these for a version with a butterfly plank stern which will be built over the next few months.
Gandelow Builders - Stories from around the World. A few people have contacted me who are interested in building the ‘proper’ 15-foot version. They are scattered all over the world. here are some of their stories:
These stories give a feel of the historical interests of our community - and of their future aspirations. More soon!
May has mostly been given over to painting out and setting up the workshop - a long job as the walls have been covered with insulation foam and so channels have had to be cut and stout wooden battens set in and bolted to the wall to give adequate support for shelving, tool boards and machinery.
In addition, all the timber, tools and miscellaneous items have been rescued from their temporary homes and brought into the workshop - it looks rather a mess at the moment but is coming together rapidly. Some excellent second-hand equipment has been purchased and restored - all a joy to use (no cheap Chinese steel!).
Figure 4 - The conversion well underway.
I have started to build a skeleton of the 15-foot boat as a way of checking the measurements we have. It will be finished next month once the workshop is fully set up. We also have found photographs that have not been examined closely since 2012 - it turns out that they show more detail than just the rough sketch below - which is good!
STOP Press: The downloads of the plans from the article on the 23-foot gandelow (published in WoodenBoat Magazine early in 2016) have topped 2650 copies! Not a mere fleet of gandelows, but an armada will set sail maybe ... ?
The first task will be to develop a set of plans showing the dimension of the boat in detail (including a ‘table of offsets’ of the parts of the boat) as none exist yet. Here’s a link to a PDF [2MB] which contains photos and sketches of the 15-foot boat built for Foynes. The sketches are rough as you can see - so there’s work to do! Also, this version has a so-called ‘tombstone’ -shaped transom (like a dory), whereas the boat we are going to build will have a ‘butterfly plank’ transom (as illustrated on this wikipedia page). Which is why there needs to be some re-design first before a model is made.
Figure 3 - Sketch of the Foynes 15-foot dory ‘gandelow’.
We’re going to build the boat in a Unit at Staunton Business Park, in Gloucestershire in the UK. The unit is a Tudor stone barn, some 400 years old, which is part of the old manor farm - a wonderful building as these two photos show. Yet before we can start boat building, the Unit has to be properly fitted out as workshop - a task that will take us into May.
Figure 2 - Workshop exterior.
Figure 1 - The empty workshop, waiting for conversion.
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[Last updated 25 Apr 2022]