16mm Projects

Roy Plum : Motorising Spooners' Boat


I’m probably certifiable, ­­­but for some strange reason at the end of the last Peterborough show I found myself thinking about the challenge of motorising a “Spooner’s Boat”.

Why would I even contemplate this?  You may well ask.  I’m just a sucker for a challenge, and having had some success at producing a motorised gravity slate train, motorising a single 4 wheeled vehicle seemed to be something much simpler.

For anyone not conversant with “Spooner’s Boat” (often just called “The Boat”), it was a contraption created on the Festiniog Railway sometime prior to 1864.  The idea was that, as engineers to the railway, the Spooners needed a mode of personal transport that could be towed uphill by any handy train and allowed to run back down the hill by gravity.  This would allow them some degree of freedom to visit / inspect any part of “their” railway without being tied to the normal timetable.

The resulting vehicle suffered greatly from the influence of “whimsy”.  Its design was very reminiscent of a boat hull mounted on 4 wheels.


It looked even more like a boat when it arrived at Boston lodge, having come down from Blaenau Ffestiniog by gravity.  From Boston Lodge to Porthmadog the railway is perfectly flat as it crosses the cob.  In order to propel the “Boat” across the cob, a mast and sail would be taken from storage at Boston Lodge.  Fitted to the “Boat” and unfurled, wind-power would then drive the vehicle across the Cob.

The original Boat was destroyed spectacularly in February 1886 when an impatient Charles Easton Spooner set off down the hill and met an upcoming train (with some degree of force) somewhere just above Garnedd tunnel.  The Boat was smashed to pieces and Charles Easton was badly hurt, as was one of his passengers.  Incredibly, the two other passengers escaped with little more than a scratch.

In 2005 the FR Heritage Society built a replica boat and it can be seen running on the Festiniog Railway at the regular “Quirks and Curiosities” week-ends.  For more details of the boat, readers may wish to visit the FR website….


Here’s an image of the modern reproduction Boat crossing the Cob.


And here it is posed in Porthmadog station with sail furled….


There are also a number of interesting videos on YouTube, https://www.youtube.com/watch?v=FXiEwWCzNb0

But let’s get back to the model now….

Two suppliers already produce a Boat….   Porterhouse Models and Timpdon Models.  I decided to go with the Porterhouse Models product, simply because it was cheaper!


I thought it very likely that I’d have to abuse the model rather severely to motorise it, so price was a big consideration as was the ease of adding and removing major structural items.  I planned to 3d print any additional “structure” needed to motorise the boat, so working in plastic seemed a better idea than combining plywood with my own 3d printed plastic.

Why didn’t I design and print my own Boat from scratch?  There are no dimensioned plans available and I’ll be honest….  drawing the structure of a clinker-built boat was beyond my skills, so £35 for the Porterhouse Models boat was money well spent in my book! But I’m jumping ahead now.

I left the Peterborough show without succumbing to my foolish desire to have a motorised boat.  You see….. I do have some degree of self-control, after all.  Unfortunately, I’d mentioned my idea to Alan Poxon so I knew that there was no going back now without loss of face.

Some months passed with all thoughts of “the Boat” very much pushed to “the back” (or should it be the stern?).  Then, completely unrelated to this project, I found myself “lurking” on the Gauge 1 3D Circle group (as is my wont) and I read that a cheap and very small Chinese single axle electric drive chassis, available on e-bay, was a useful starting point for various projects.

This was the item in question:  https://www.ebay.co.uk/itm/254942541046?var=554822692259


For £7.78 those wonderful people in China would send me a “dual shaft” drive system of 3, 6, 9 or 12 volts with one of four permutations of reduction gearing.  I thought 12v drive seemed the best option and this was available with outputs of 16 rpm, 68 rpm, 136 rpm or 381 rpm when running at full voltage.  I decided to buy 2 systems for test purposes… one of 136 rpm and one of 381 rpm.

A few weeks later the package arrived and I was very impressed with what I’d bought. It was very nicely made, very small and very neat.  The main drawback was that the 2.5mm diameter drive shaft protruding from either side of the gearbox was just 30mm long.  With normal back-to-backs being 28mm on 32mm gauge, this didn’t allow for much axle to pass into each wheel…  just 1mm in each wheel, in fact.

I drew a simple mounting system (just a bracket, really) into which one of my new purchases would fit.  I decided on a simple push-fit.  If the bracket didn’t grip the motor then a touch of glue would be my solution.  Here’s the design….


I was in luck and the bracket was a tight fit on the motor and the whole thing worked fine without resorting to glue.  This meant that the drive system could be quickly replaced if it failed or I wanted to experiment with other voltages and gear ratios.  All I had to do was to gently lever the old motor assembly out and push the new one in.

Having seen how neat and small this solution was, my thoughts turned back to Spooner’s Boat.  This system could be fitted to the boat in a very unobtrusive manner….  so with no time to loose, I ordered a boat from Porterhouse.  I added a note to my order to the effect that I would prefer an un-made kit of parts as I was likely to be butchering the model anyway.  Mr Porterhouse only sells his 3d printed models in “made-up” form and no doubt my proposal horrified him, so a few days later a complete assembled boat arrived in the post.

Examining the model, it was made of 2 parts….  The upper boat body and a flat 2 axle chassis.  The two parts were attached by a single, small, self-tapping screw right in the centre.

I decided to keep the original chassis “as supplied” as it could be used under the boat body to attach the boat to the rear of a passing FR train for haulage up the line, just like the prototype.  I’d design and print a second chassis to which I’d glue my motor drive on the underside.  Luckily, when I did this I found that the axle centres on the motor drive were in exactly the right place!  What I mean is, they sat at the same height from the rails as the second unpowered axle, thus keeping the boat level (or may I say “on an even keel”?).

I needed to print a new set of wheels for my powered chassis and I noticed that the prototype had seven spoked wheels whereas the Porterhouse wheels were six spoked… so I fixed that small error and decided to extend the wheel hubs (with 2.5mm dia holes in them, to take the drive shafts) behind the wheels towards the gearbox.  The idea was that, although the Chinese drive shafts were a bit on the short side, enough of the wheel hub would slide down the shaft to hold the wheel true and the tight fit would stop the wheel coming loose.  This is the design I’m trying to describe…..


In practice, I found that the hubs that I’d designed were too thin to take the force of the interference fit on the axles and they split apart!  I increased the thickness of the hub wall and this cured the problem.  No-one notices that the inner hubs are much wider than the outer hubs, so don’t tell them Pike!   This is how the project was looking at this stage…


Also notice how the original self-tapping screw holding the floor and boat body together lies under the end of the motor.  This was the only significant problem I encountered in the whole project.

Next job… add a battery and some kind of on-off switch.  The boat body has two empty box-like structures on it, these being the forward and rear seating areas.  The front box is not quite empty as it has the mast mounting hole projecting into it.  I decided to leave this “as was” because I wanted to have a demountable mast on my boat.

The rear box was just the right size to take a small 11.1v 350mAh LiPo battery, so that was a good start.  What was a real problem was that the self-tapping screw that fixed the chassis to the body was half hidden under the drive motor.  This was clearly no good at all as I intended to regularly remove the chassis from the body.  This would be necessary to charge the battery and to swap the driven and non-driven chassis to suit my requirements.  A bit of re-modelling was therefore undertaken.

My favourite tool for fixing small errors on my 3d prints is a soldering iron.  This softens the plastic enough to re-shape it as required.  A bit of judicious re-shaping soon saw the central fixing mount for the self-tapper flattened into oblivion (well, generally smeared around actually) and I also cut though some very small ribs on the original model to allow passage for the wires to be routed from the battery into the front “box”.  As I’m not a fan of self-tapping screws in my models I was glad to see the back of that idea.  I added a small BA nut to the upper body (just superglued in place) so that I could fix chassis and body together using a cut-down 6BA screw.  This new fixing point was moved about 5mm to the rear of the boat so it was now clear of the motor and thus very easy to access.

At this stage, the boat body looked something like this…..


The electrical tape binds the wires close to the battery, keeping the assembly as small as possible so as to fit in the rear box cavity.

As all this work was underway I became very concerned that I might break the fine scroll-work on the boat’s upper deck.  I therefore printed a “support fame” which provided a base for the upturned boat body, holding the scroll work clear of the workbench and taking all the forces of my ham-fisted efforts.


Next came the problem of adding a switch to stop and start the boat.  I wondered about using the lever near the front of the boat as a switch toggle.  This lever is the brake lever on the prototype.

This all seemed a bit of a difficult and potentially messy solution.  Then I remembered that some years ago I’d read in SMT of someone who’d used a small remote control system designed for Christmas tree LED systems to control his 16mm locos.  I also remembered that I hadn’t really understood the article, but that I’d purchased a ready-wired equivalent system at a model engineering show from a supplier who must remain nameless.  Luckily, this system fitted inside the boat front box cavity.  Unluckily, it didn’t work.

I investigated the whole idea a bit more.  I downloaded the relevant article from SMT (Issue 157, Feb 2016) and with my new incentive to get-it-right I sussed it out.  I found that I could get matching sets of TX and RX units on e-bay from our friends in China for just £2.64p…. yes, you read that right!

Here’s the link:  https://www.ebay.co.uk/itm/233620671277?var=533304663574



(Are you becoming in-tune with my mind now?)

It seemed like a worthwhile punt to buy a couple of these systems to experiment with.

A few weeks later they arrived and after a little soldering I’d got one fitted, and this time it worked!!!

What this gave me was on-off and speed control in one direction… which is all I needed. The real boat never ran backwards unless it was being towed! The units claimed a wireless range of a few metres.  In practice, I found it to be more like 2 to 3 feet.  They do say that you can add an aerial to the PC board to increase the range, but I ain’t tried that yet.

Another problem with the system is that there’s no slow crawl speed.  It’s stopped or it’s doing 15mph.  After that, the variable control is pretty good up to full speed.

Here’s the system with the chassis floor split from the upper body.  The PC board is the remote control receiver. A small lump of brass adds ballast weight over the front driven wheels.


All that was left to do was to add a suitable mast and sail.  I decided that I needed….

  • A mast and a furled sail….   This to be laid on the boat when being hauled behind a train from Porthmadog to Boston Lodge.
  • A mast with full sail….  To be used to power the boat by wind when travelling from Boston Lodge  to Porthmadog or vice-versa.

These systems were duly printed and added to the model.


My attempt at a “billowing sail” was produced by 3d printing a thin, flat sail shape which I then held over a boiling kettle for a few seconds.  This softens the plastic enough for you to deform it with your fingers and hopefully the ensuing product is good enough to fool someone with poor eyesight on a foggy dark night.  I “squashed” the furled sail in a similar manner, so as to give it the “undulating” appearance of casually rolled sail material.

That’s about it.  It turned out to be a particularly pleasing and enjoyable project….  in part, because the whole job only cost about £50 all-in including the Porterhouse model, the £6.25p LiPo battery, the motor drive and the remote control system.

You may ask why my model is buffer beam red and not the lovely deep crimson of the actual boat?

Well, the cap on the rattle can was a lovely deep crimson.

For readers who would like to see the 16mm boat in action...  here's a video clip:

December 2023

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