afloatoct2006


Let's start with a little factual information: This is the Hobbies Arrow Steam Launch, christened "Môr-Forwyn" (Welsh for Mermaid), and built by myself during May, June and July 2006. She's made out of obeche, pine, mahogany and aluminium. The steam plant is a 1950s SEL Marine engine powered by a 1930s Bowman 135 boiler. The hull is 24" x 4.5" beam, and she weighs in at 1.8 kg dry including radio and batteries. 

The first I heard of Arrow was in the autumn 2004 edition of Bowman news. This magazine included an article by Martin Flegg, then the Hobbies Development Manager, detailing his new design of a steam launch strongly based on the Bowman Snipe, but with considerable improvements to the hull, and now with radio control - not an option in the 1930ies! I read the article with interest, as I'd wanted a Bowman boat for a long time but had been unable to afford one, but put the thought of building one out of my head as one of those "haven't got the time/skill/tools" things. Of course there exists a long and venerable link between Hobbies and Bowman - I believe the two companies once shared premises, and certainly early Hobbies steam engines were made by Bowman, and the wooden hulls for Bowman boats made by Hobbies. Hobbies is unique in that it is perhaps the only business of its kind still around, as it has been for well over a hundred years!

Fast forward now to April and May 2006, and yours truly is having, with some understatement, a "spot of bother" that's earned me several long-ish and painful hospital stays, and sees me laid up for protracted periods of time with nothing to do so....with a spare 135 boiler sitting on a shelf, my mind started ticking, and I decided to order the plans from Hobbies. I also had some communications with their director Andrew Meek, who gave me some gentle encouragement. My first reaction on seeing the plans was a profound sinking feeling....this was no "put it together" kit, but a scratch build - with my non-existent skills in woodwork a daunting prospect.

I studied the plans very carefully for several days, and played the build out in my head. After a while, I'd convinced myself that I could possibly bring this to a successful completion, or at least have fun doing it. So I bought an electric fretsaw on EBay, and ordered the raw materials and some tools from Hobbies..
In the meantime, I was slowly getting better. In fact, my recovery became linked with my progress in building the boat. Every day I got a little stronger, and built another bit. I had to learn a whole new set of skills, and therefore took it nice and steady. To my amazement, nothing actually went wrong! During the build, I kept an extensive photo diary which can be seen here.

The engine I had originally planned to drive the boat turned out to be not quite satisfactory, so a replacement was found in the SEL Marine Engine, which was provided by IndianaRog. On August the 22nd Môr-Forwyn had her maiden voyage, which was a total success - footage can be seen below.


"Arrow" Build Diary

I've wanted a Bowman boat for a long time now, but with current price trends these are, unfortunately, totally out of my reach. Even if they weren't, I'd be very hesitant to retrofit 200 pounds worth of antique toy with radio control and chuck it in a pond. So, when Hobbies of Dereham announced their "Arrow" steam launch kit, based on the Bowman Snipe, my eyes popped wide open. My woodworking skills are pretty nonexistant, so it took me a while to bite the bullet. What finally prompted me into action was getting hold of a redundant Bowman M135 boiler, and a period of enforced absence from work due to illness.

I ordered the plans, and soon worked out that this would require some serious investment in time and tools! In fact, with what I'm spending on this all together I could probably buy an original Bowman! I've no regrets though, as this will give me the satisfaction of having something completely made by myself - means I can also modify it to my heart's content!
So wood, blades, fretsaw, pins, tenon saw, glue and who knows what else where duly ordered from Hobbies, and arrived in record time. One major-ish investment I made was buying an electric scroll saw, which I highly recommend - a fantastic labour saving device. With that saw I can do in an hour what would take me a week with a handheld fretsaw.

What follows is a photo diary of the build as it happens. As with all my projects, this will run in fits and starts - long periods of inactivity followed by leaps of progress. As I'm learning new skills while doing this, it will all take me longer than it would a seasoned woodworker or modelmaker. I'm very much of the "measure twice, cut once" school, as I really want to avoid mistakes as much as possible. So bear with me, and keep your fingers crossed (and out of the way of those fretsaw blades ;-)!

Peruse at your leisure, or go straight to the latest entry

For the page with the finished Arrow, click here.


May 25th, 2006
running-in

The Bowman M135 boiler that I intend to use, shown here during running in of a little UNIT oscillating engine. During running in, I discovered a port misalignment, so this engine is currently awaiting replacement.


May 27th
marking-out

Me in a slightly hairy state transferring the plans onto the wood. Slightly tedious little job, but extremely important. I photocopied the plans, cut out the individual parts and traced around them. Further detail will be filled in later using carbon paper.


may 28th
fretsaw

This electric fretsaw is a wonderful tool. I am not confident enough to use it for intricate shapes, but for long cuts and right angles it is absolutely ideal, and a real time saver. Shown here is the rear servo platform being cut out of 9mm pine - took me about 2 minutes!


May 29th
bowandbulkheads

A most productive little sawing session. All the big parts have now been at least roughcut, and some are very close to finished. Visible here is the bow support and three bulkheads. The area behind the main bulkhead is where the steam engine will go. This is about 2/3 of the lenght of the actual boat. You'll notice the hand fretsaw in the background - I'm using this for the fine work, such as cutting slots.


May 31st
stern

Made some serious progress! Did all the fine cutting on the stern fittings, and then spent about an hour filing the mitre on the rear plate just right - hard work, but worked out well in the end. Don't trust myself to do it freehand, and the angle is too shallow for a mitre saw.Also today received a beautiful brass container which will serve as an oil/condensate trap. Made by Paul Walsh, who trades on EBay under the name kitcarsupplies.


June 1st
The replacement for the little UNIT steam engine mentioned above arrived today, direct from Tony Green Steam Models -excellent service! Spent most of this evening running it in, it now runs very confidently in both directions, at a solid steady spead.


June 2nd
bow

It's now getting obvious where this is going. Making fine adjustments to bow brace and bulkheads to ensure a dead fit. You'll also notice that the main bulkhead is now freestanding - this will be cut into an arch to acommodate the steam engine burner.


June 4th
One critical job's finished - I've drilled the hole for the prop shaft. Very tricky, as it involves drilling a large hole at a very shallow incline (25 degrees) through 9mm wood. Managed it starting out with the Dremel and graduating to a handheld drill.
Also ordered the R/C Gear plus a glut of rechargeable batteries to go with it.


June 6th
sternservo

Made final adjustments and fitted/glued the stern assembly - in this picture some of the glue is still wet. I also have the habit of brushing a little sawdust into a glue join - just that bit of extra strength. The propellor tube is also visible here, along with a little servo just dropped in for show. The set square shows everything's nice and level. R/C kit arrived today - I went for a HiTec Ranger 2N on the 27MHz band - easy to swap crystals should the need arise.


June 8th
Fair bit of work tonight, but nothing really photographable. I cut a bridge-shaped (rather than solid) main bulkhead, to allow for the steam engine burner. As this is freestanding, I glued and brass pinned it to hold, and it is now very strong - if you tap it it pings like a piano string!

Also cut and shaped the receiver support wedges - without these, the receiver could slip into the innards of the stern and get wedged behind the prop shaft. I cut and fitted the rudder skeg, but on a trial fit I found that the rudder did not align perfectly with the prop, so spent a fair bit of time filing this out to a very precise fit.

Most interesting exercise was a trial in fitting the boat's sides. These are cut out of 6mm seasoned pine, and have to follow a couple of curves. The raw material isn't exactly bendy to say the least, so the instructions say to make shallow tenon cuts across the grain in about ten strategic places. I tried this on a waste strip, and it works an absolute treat - cut about 3mm deep with my tenon saw, and the result is bendy indeed - not quite flexiply, but certainly bendy enough to shape it without fear of cracking or splitting. Clever trick!


June 9th
sides

A trial fit of one of the side panels. After some experimentation I decided to make a few extra tenon cuts close to the bow, for a bit of extra flexibility. Goes on easily enough, with some judicious clamping. Found out that the sides are about 7mm too high - not sure if this is part of the design so they protrude a little at the bottom, so I need to find this out before I glue them in.


June 10th
testfit

Half an hour to burn - decided to do a testfit of all the bits to go in the boat. Left to right: Battery pack (needs extension lead making), Bowman M135 boiler, UNIT steam engine, servo, receiver. Not shown: burner (currently drying outside ;-) On the screen: this diary, of course!



June 12th
bothsidestest

The mystery of the too-tall sides is solved ;-) As I suspected, they're drawn a bit generously on the plans. Andrew from Hobbies (who couldn't have been more helpful through all this) confirmed this for me, so I had little hesitation in taking the fretsaw to the sides and lopping 6mm off each - they now fit absolutely perfectly with just over 2mm clearance over the bulkheads. What you see is another test fit - I'm trying to work out the best way to clamp the work before I glue it. There's a fair bit of tension going on here, and some of my clamping attempts were rewarded with slapstick like moments such as one of the sides smacking me full in the nose - complete with humorous "SPANG!" noise! Never mind though - this is beginning to look suspiciously like a boat!



June 13th
lotsaclamps

From this day onwards, this method of attaching one of the sides shall be known as my "Lotsaclamps (tm)" method! After a bit of experimenting I decided that this was probably the only way, one side at a time with at least 24 hours inbetween. So I borrowed two very mighty clamps (many thanks to Rorie Brophy of RWCMD Design Dept.) to add to my own arsenal, and applied glue. Lots of it. Also, as per the plan, a mixture of glue and sawdust in the tenon cuts.
So.....now we wait.....


June 14th
leftsideon

It worked a treat - that "Premium Wood Glue" is something else, worth every penny. Just to make extra sure, I used a number of tiny brass countersunk screws for just that bit of added security - wouldn't want one of the sides to jump off while in the water. Anyway, in the plans it says "brass pin to hold", so I don't feel I've deviated too far here.


15 June

bowfit

I always knew that fitting the second side would be tricky - as it is at such a sharp angle, there is no way of clamping the bow directly. So instead, I Improvised a variable angle strap clamp, using two bits of scrap hardwood, secured to the bottom of the bow by a wedged clamp, and to the top by first some strong packing string, wound around the clamp that secures to boat to the workbench. I then closed the "clamp" by winding it tightly with more string, and finally wedging it with another offcut. A bit Heath-Robinson, but it looks to be working well. I'm away on the weekend, so we'll find out more on Monday.


June 18th
hulldone

It worked! I now have a working hull, and I'm very, very pleased - I never thought I'd get this far. Lots to do still, of course, but I think this really is the hard bit done.
Another bit of good news: the search for lead is over1 My father in law, the inestimable Mr Bob Ford, had some offcuts in his shed!


June 20th
Nothing really photographable, but progressing well. The hull is now 100% complete, any little gaps filled, and the bottom made waterproof by filling the tenon saw slots. All the glue work has held beautifully, and the hull sides are also secured by a number of little countersunk brass screws, which will be invisible once painted - the hull should appear as out of one piece, at least externally. I have now also fitted and backfilled the rudder and prop, complete with skeg for the propshaft. The hull is now ready for painting, and cutting of deck trim.


June 22
primer

Now reaching a very satisfying stage of the build, where most of the work to be done is just cosmetic. Here you see the finished hull drying under its first coat of primer (I'm using JapLac). Really brings out the nice clean lines....can't look at it without thinking "wow....I made that!" ;-)


June 25th
Well, here we are, one month into the build, and it's gone a lot quicker than I thought. Nothing really to photograph really - I'm currently painting the hull, British racing green and white. I'm taking my time with it - I want this boat to look absolutely fantastic when I finally unveil it. Watch this space!


June 27th
waterline

Arrow in its current state, complete with white painted waterline. Still needs gold pinstriping and deck trim




July 1st
decktrim

Cut the mahogany deck trim - not a very difficult job, but precise and calling for very exact marking out, as it needs to follow the shape of the hull exactly. The rear deck is in two parts, glued together down the centre. Also applied the gold pinstriping (not shown in picture).


July 3rd
morforwyn

In essence, it's finished! I've fitted the trim - the back deck has been varnished, bow trim still to do. Also did the gold pinstriping and cut the the spray hood (still some tweaking to do). Perhaps most importantly, I've decided on a name  - it's going to be "Môr-Forwyn", which is Welsh for "Mermaid" - Millie the Moose's favourite mythical creature!

Still to do: more varnishing, fitting the R/C gear, finishing and fitting the steam engine - enough to keep me happy for a bit. Getting there though!


July 7th
enginerunning

Another important job done - I assembled the engine. The engine is a UNIT steam engine, slightly modified by myself, fitted to an aluminium base reinforced with a couple of cut-down meccano girders. The boiler is a proper Bowman boiler, this one was part of an M135, and is identical to the boiler originally fitted in the "snipe" launch, upon which Arrow is based. The boiler needed a couple of small repairs such as a new steam pipe fitting. The engine is still running in, but is now a good and strong little runner. I may file an oil groove into the piston at some point, I haven't decided yet. Picture shows the engine running - the blur at the end of the flywheel are the pins that will engage the propshaft.


July 9th
rc

Easy little job, but critical - fitting the radio control. I'm not bothering with speed control on a single oscillating engine, as I don't want to run the risk of stalling. So all that needed doing was to shorten the rudder arm for maximum radius and make up the servo linkage. I still have to find the optimum place for the aerial, as running it underneath the aluminium engine base sends the receiver nuts!


July 12th
arrow first run

Pretty exciting moment - first run under steam, and all the signs are good! Click on the image for a little movie (2.2 Mb)


July 13th
me

Well, I'm going to have to face the facts and accept that she's finished....I'm going to need another project soon! In the meantime, there are still a few small refinements to do, and then I need to find a good opportunity for the maiden voyage. In the meantime, to my delight Hobbies has asked me to write a few words about my experiences, and this is sort of a publicity shot.


July 14th
stand

....but of course there are always still little related jobs....I knocked this little stand together out of some of the leftover bits of wood. A couple more coats of varnish, and a nice bit of green felt will finish it off nicely, and I may even invest in a little nameplate.


July 22nd - Maiden voyage!
arrowtrip

Well, Arrow has had her first couple of minutes in the water, and first results are promising, with a few minor problems to be ironed out. First and foremost, I am going to replace the engine - although it is a good runner, it just doesn't get the revs up for anything resembling a decent speed. I have already found a replacement in an all-brass SEL marine engine that was originally sold with the Mamod ME3 plant - currently in IndianRog's collection, but soon to be this side of the ocean, thanks Rog!

Secondly, the burner needs revisiting. The standard Bowman burner is just not suitable for open air use. The problem I had was that the hot gas vented through the venthole in the filler plug caught alight in the confined space of the hull. I then foolishly plugged this, with the result that the expanding gas was pushed out through the burner tube, resulting in a rather pretty but very hot fireball! Fortunately this happened with Arrow ashore, and I had it extinguished before any damage could be done (I'm not counting a strip of melted Velcro ;-).

I may fix this by incorporating a vent tube which will carry the hot gas safely into the atmosphere. I'll also make a little hood that will shield the burner from the direct heat of the boiler. As a last resort, I might run it off solid fuel. We'll see. All these things are teething problems, and I'm sure I'll have them sorted out before too long - keep watching this space!


July 27th
selmarine
Engine number three! This one's from IndianaRog's collection. This engine was made by SEL towards the end of their production, and for a while Mamod used it in their M.E.3 plant, but for one reason or another it was not considered succesful.

I've comprehensively tested this little engine, and I have to say that I'm very impressed - don't quite see what the problem was with the Mamod plant. Coupled with my 135 boiler it goes like a bomb, very high speed and significant torque at the output shaft - not at all easy to stop by hand!

This engine's pretty much in new condition - it obviously has never been connected to a boiler, as I had to solder in a couple of steampipes - there was no evidence whatsoever of any previous soldering.

It's a sturdy little beggar, quite heavy and with a surprisingly large footprint. Fitting it to Arrow's going to be a job, but I reckon one worth doing.


August 14th
seltrial

Finally had some quality time to spend on the boat...pesky things like family holidays kept getting in the way ;-)

I've made a purpose-buit platform for the SEL engine - as it is so much more powerful, I didn;t want the chance of it vibrating free. To that end, I built a reinforced wedge out of mahogany. It is strong enough to take my full weight (!), yet weighs next to nothing. This is held in by a couple of 4mm bolts driven through the hull, sealed with fibre washers.
I made a marine type coupling by soldering a couple of brass pins to a 1/8" shaft fitting I had lying around (actually a splined universal coupling insert cut to size). This mates up to a 3mm thick neoprene disc on the propshaft, which has a couple of slots cut out to accept the coupling. There is enough free play in this to eliminate the chance of seizing, but it's tight enough to prevent any loss of energy. The boiler platform has been cut short, and I've cut a couple of Jensen insulating boards to size, and they fix to the sides with velcro.

I've testfired this arrangement "in the dry dock" several times now (see picture), and it appears to be working superbly well. The SEL engine is a very fast, very strong and, importantly, very clean runner. I'm currently using solid fuel, which works well, but to make absolutely sure I have no further burner mishaps I will fit a ceramic gas burner.


August 17th
arrowbath

It's bathtime again! Click on the picture to see a short movie of the SEL engine running in the water. Play it side by side with the movie of the UNIT engine to see the difference.


August 22nd - Maiden Voyage 2nd attempt!
arrowmovieicon


Well, the conditions were so perfect today that I couldn't wait any longer! Arrow ran beautifully for 15 minutes, without any stalling or protesting. That combination of Bowman boiler and SEL engine's a winner. Watch the footage, says more than 1000 words.


August 27th

gasburnerstern  

CeramicBurner60065sml
Received the gas burner from Forest Classics today - initial impressions are very good indeed. Fitting and setting it up was an absolute breeze, and I now get 25 minutes of constant, clean heat on a single filling.  It runs much hotter than any meths or solid fuel - it'll bring a cold boiler up to steam in a couple of minutes even ata low setting, and the engine runs like a demon. The match with the Bowman boiler's perfect - I fill it with 125cc of water, and when the gas runs out after 25 minutes, there's still 35cc of water left - a comfortable safe margin.
I've made a heatshield out of some aluminium and a Jensen insulating pad that keeps the burner and gas tank well separated - it just attaches to the bulkhead with a bit of Velcro. The tank stays completely cool - in fact it gets pretty cold due to the gas evaporation.