LMS Dock Tank

LMS Dock Tank
Originally uploaded by Phil_Parker

The Dock Tank is finished. I usually say that I build locos for people that I would be happy to run on my own layout. In this case I can confidently say this is the case - my original version of this locomotive isn't as good as this one !

If I need an excuse it's that the Mercian kit is one of the more challenging on the market. It could scarcely be anything else with all that waggly stuff under the footplate. The prototypes' cab design doesn't help either. What was wrong with proper cab sides and roof ? Since this was my second go at the model, I had learned from my first attempt. Also a good few years had passed and my skills and equipment are both much improved.

Of course all this contributes to the charm of the model. In 4mm scale it looks good. The G1 version is even better - but just as tough a build I'm told thanks to the tight clearances in the valve gear. It just goes to show that as you get older, moving up scales so "the bits are bigger" isn't always a smart move. Us OO modeller at least have the advantage of a bit of lateral space where it matters.

Finishing touches

Coal
Originally uploaded by Phil_Parker

I normally leave coaling up a model locomotive to last. It's a tradition that says that everything else is done and the finishing line is in sight. Of course I have used proper, real, welsh steam coal (get in touch if you would like to buy some as I have a big bag) held in place with a PVA/water/washing up liquid mix. It's just sparkly enough to look right, something other types of coal don't always manage.

Fortunately the bunker was water tight. PVA leaking out over the paintwork isn't much fun. Ask me how I know...

Fitting tension lock couplings

coupling - front
Originally uploaded by Phil_Parker

The Dock tank specification includes a set of standard tension lock couplings as fitted by Bachmann or Hornby - in fact a pair of Hornby spares were provided. All I have to do is nail them to the locomotive. Normally I use Spratt & Winkle on my own stock or bits of bent wire. Doing the job properly is unusual and needed a little thinking.

Tension locks usually sprout from somewhere under the buffer beam. There are standards for height but I simply used a Bachmann wagon as my guide. Even if you follow the recommendations to the letter I don't think the job is done until you have tested with real live rolling stock anyway.

At the front, fixing is complicated by the chassis - it's in the way of the pivot. This is turned to my advantage by cutting a couple of slots and bending the spacer up to provide a fixing point. A 10BA bolt hold the coupling in place. I felt it was sensible to allow for the removal of the items should the owner wish to change over to something else in the future. Besides you don't want the glue joint giving up on this the moment you try and shunt a heavy train do you ?

The back was actually trickier. While the chassis isn't in the way it also doesn't provide anything in the way of support. A small bracket that makes use of the body fixing screw does the job here. It will mostly be hidden by the buffer beam anyway so no one will nitice I drilled the top hole in the wrong place first time I hope. For clarity a brass nut stands in for the body and allows me to test things without risking my nice paintwork.

The chassis now couples to my wagon and hauls it up and down the test track happily enough so it's time for the finishing touches.

Varnished Dock Tank

Varnished Dock Tank
Originally uploaded by Phil_Parker

Hooray for slightly warmer weather. A sunny day made me brave enough to waft some Humbrol satincote varnish over the dock tank. OK so there was still a lot of hair drier action to get things dry before any moisture could get into the coating but at least this allowed me to carry on working.

I've deliberately kept the coat thin. Partly because this is what all the professional painters advise and mostly due to my nervousness about needing to strip the model if it all went wrong. The result looks nice though and that varnish will protect the transfers. Buffer beams and body finally have the same sheen despite the former being painted in gloss for a better colour.

Jobs to do:
Glaze the windows
Paint the buffers
Paint cab floor
Fit couplings
Add coal
Reassemble and test

Pressfix Transfers

Another make or break moment for this model locomotive - applying transfers. In stock I had the appropriate Pressfix LMS locomotive sheet. These decals give the best result because there is no transfer film around the letters. It's just that I struggle with them.

According to the instructions you lift the top layer of the transfer from the sheet, prod it into place with a final hard push and then float the transfer sheet off with some water revealing a beautiful letter, number or crest. Fine in theory but I'd always assumed that one the thing was in place, that was where it stayed even if you'd got it slightly wonky. Fixing this meant taking off the transfer and using a new one. Since you couldn't get a clear view of whatever you were applying until the paper was removed this made an important job more challenging. Wonkiness would also be inversely proportional to the number of transfers left on the sheet multiplied by your chances of getting more before the model was required. Guess how I know this ?

Apparently I was wrong. While trawling Stafford show for waterslide transfers I chatted to Graham Shaw (now ex-Shawplan models) who gave me a hint. If I mixed up a 3 part methylated spirit: 1 part water mix, this could be brushed on the transfer once the top sheet had been removed and allow me to move it very slightly. Or I could just drink the mix and I probably wouldn't care how wonky the letters were*

And it works. Thanks to a clear plastic guide I managed to get the LMS on first time (in the photo I've not held the plastic against the footplate because I needed a hand for the camera but in used I'm careful to make sure it's in the right place) but the numbers needed a little gentle lifting and prodding to get the best alignment.

Mind you if you can find waterslide then having transfer film showing isn't all that unrealistic according this photo.

*Kids, methylated spirits should be enjoyed responsibly.

Painted dock tank

Painted tank
Originally uploaded by Phil_Parker.

Finally, the dock tank has paint. Cold weather over the last few days left me wary of the unheated, broken Beetle filled garage I have to paint in. Try spraying when the mercury is too low in the thermometer and the paint will bloom. Snow on the ground basically means no spray painting.

Sunshine on the other hand means I ought to be OK. To be on the safe side I used my big compressor which has a moisture trap fitted to the outlet.

This locomotive is to supplied in ex-works livery so the paint employed is Precisions's matt black. It's not as matt as Humbrol and a pretty good match for a Bachmann paint job as well if you need to do any touching up on a RTR model. Thinned with white spirit (too cold for cellulose) the coats went on evenly and dried quickly enough with the assistance of a hair drier. The finish is best described as eggshell which ought to be OK for the transfers. A final coat of satin varnish will complete the look.

Still looks like a Jinty

Primed dock tank
Originally uploaded by Phil_Parker.

The dock tank has been primed. Then tinkered with. Then primed again.

And it still looks like a Jinty !

Holey bottom

Holey bottom
Originally uploaded by Phil_Parker.

Locomotives built from etched kits are normally too light for reliable layout operation. While I like to test them without extra weight (if they work without it, they work even better with it), one of the last jobs before painting is to stick some weight in wherever I can.

The dock tank locomotive is well placed for weighting. The side tanks are nice big boxes which you could fill with lead or any other heavy material (uranium anyone ?). Sheet lead put in during assembly would probably be best but to allow the lightweight testing I decided to drill holes in the bottom and pour "liquid lead" in instead. This is followed by some glue to hold the tiny lead balls in place.

A word on glue - don't use PVA as it can cause the metal to swell. I've seen a 7mm scale GWR 0-4-2 with the smokebox blown apart because it had been liquid lead'd and PVA'd. I've used a cheapo "Liquid Nails" style glue. It is supplied in a tube with a nozzle - which gave me the size for my holes as I used this as a funnel for the lead before forcing the glue in.

Once the glue is in, the holes are covered with masking tape and the loco set the right way up. This should allow everything to dry in the right place. Tiny lead balls find all sort of ways to escape and I know from experience can bung up a model gearbox !

Squeezing the brakes in

Brake close up
Originally uploaded by Phil_Parker.

Oh the joys of a reduced size etched kit. I'm sure that the brake shoes and hangers weren't this much of a squeeze to fit in in 7mm scale. Of course the larger scale people aren't using Romford wheels which might be a touch over scale.

As supplied the parts neatly fill the gap available in a complete and short circuit inducing way. Since I've been asked for a running model and not one that will blow every fuse in the house, this needed a little attention. The back of the shoe was filed back the hanger, the front reduced by about 1/2mm and then the shoe re-profiles with a half round needle file.

And did the designer of the prototype have to put front brakes on ? I mean this is fiddly enough as it is without tucking the things behind the cross heads !

Mind you, once all the gear is in place it does look nice.

Coal rails

Coal rails
Originally uploaded by Phil_Parker.

Lots of head scratching here. I know where the coal rails on the locomotive but how I was to get them there was a little more challenging.

As supplied the part has all the strength of thin paper. To give some relief the rails are mostly half etched. I don't understand why as the alternative part is made from whitemetal and the thickness of (scale) tree trunks. Full thickness brass would have been a whole lot easier to handle.

Anyway, I tinned the part to beef it up a little and then used the RSU to attach the back and ends. They seem pretty well fixed but the whole thing is still a bit flimsy. It's position on the back doesn't help as I keep bending them. I know they can be straight but will leave that until spray time to avoid messing up the metal with constant tweaking.

Still, the guards over the back windows look nice, don't they ?

Resistance isn't futile

Tank top
Originally uploaded by Phil_Parker.

Now I'm onto the detailing stretch on the dock tank I've broken out my resistance soldering unit (RSU). Not a tool I use very often but it comes into its own for this sort of thing.

The photo shows a riveted plate and lug fitted to the top of the tank. To use the RSU I tinned the back of each part with the conventional iron, smeared flux on the tank and then holding the part in place with the RSU probe, pushed the foot switch. This makes current flow through the probe and then the part and solder. The solder heats up to melting point. Then I take my foot of the switch while leaving the probe in place. That allows the solder to cool and fix the part.

This is much easier than doing the same thing with a normal iron. This tool has to be removed to take away the heat which means another way of holding the part in place is required.

Best of all, little or no cleaning up of excess solder is required, a blessing around the little bits like this !

Roof resolved

Roof resolved
Originally uploaded by Phil_Parker.

Off the roof came and this time the cab back was removed too.

The roof wrapper was still reasonably accurately bent so I just heated up the solder to smooth it out and made a new sub-assembly of roof and back.

Then the cab back was shortened by filing it down to remove the excess 3/4 ish of a mm. I suppose I should talk about careful measurements and highly accurate cutting but to be honest I just kept trying the part on the model until things looked right. Then when all appeared OK I tacked it in position and measured the height back and front with a dial vernier. The numbers came out the same so the joints were made good.

With things still OK the beading around the opening went in. This is a thin strip with a half etch line down the centre to aid location. It's tacked in place and jiggled into perfect position. Finally loads of flux, heat and a tiny amount of solder later it's in. One side needed a little adjustment as all the messing around with the roof had stretched the side a bit. The result, when under paint should (I hope) be invisible.

Cab roof

Assembled roof
Originally uploaded by Phil_Parker.

Re-scaling etched railway kits opens up many possibilities. With a few button pushes on a photocopier or CAD package models can be made available in different scales with only a small investment in castings by a manufacturer. Obscure scales rely on this for trade support - many 7mm kits have been shrunk to 3mm which allows those of us in the smaller scale to enjoy a wide variety of locomotives that we otherwise wouldn't have a chance at as we simply wouldn't generate enough sales to justify creating the kit in the first place.

Sadly, just because you can produce something, doesn't mean it is buildable. The parts always scale, the concepts are less reliable.

On the dock tank the cab roof is in 3 sections. According to the instructions you attach the sides and clip the centre part in as required. This way the cab interior is accessible for painting - A Good Thing. In 10 and even 7mm scales I can see this working. 4mm modellers struggle. It's another case of a prototype that doesn't make life easy for a model maker. The roof doesn't have the normal lines and instead is more like a continuous curve. Result; the tops of the sides have to bend in smoothly yet there is little metal to grab hold of to form the curve.

I fiddled with this and eventually gave up. The sides came off the loco and I turned the entire roof and sides into a single part. This was then bent up over screwdriver handles (the bend occurs just above the top of the cab doors gap) with the gentler top bend made with fingers.

All of this means the soldering had to be done from the outside. Lots of flux and tiny amounts of solder were employed to keep cleaning up to a minimum. At this point things were looking good.

Then I sat back and looked along the loco. Now I appreciate that I'm not completely intimate with every single member of this class of locomotive but I'm pretty confident that none ever visited a custom car shop and had a sporty rake applied to the roof for aerodynamic or style purposes. Certainly the one I'm building didn't. It appears that the cab back is taller than the front by just under 1mm.

Hmmmm.

Firebox fun

Whitemetal firebox
Originally uploaded by Phil_Parker.

The dock tank locomotive firebox is giving me trouble. My intention was to use the cast whitemetal top supplied. It would have the right bulk, curve properly and add a bit of weight in the right place on the model.

As you can see from the photo, this was not to be. Having bent the casting back to flat and tried it in position there was no chance of fitting the thing. It was narrower than the boiler for a start. I know whitemetal shrinks as it cools but I have a suspicion that this one might be intended for the HO scale version of the kit. Mind you since the instructions don't make any mention of the part, then perhaps its inclusion at all was a packing error.

Aside from the reasons listed above the main factor behind my choice was that I didn't believe the etched firebox would work. It's formed from a half-etched wrapper with little corner pieces. The wrapper was pretty flexible and prone to creasing. The corner bits were tiny and had no locating tabs. All I could do was gip them firmly in some tweezers, heat some solder and poke them into position hoping I got it right.

First though, the wrapper was bent over a small screwdriver - the bend falls along the line of washout plugs making this work even trickier. Then I started poking hot metal around. The first corner worked well. The second took a couple of goes. Then I fixed in the washout plugs which are on a plate fitted behind the wrapper. And one of the corners fell out.

Much poking and cussing later the part was formed and once trimmed, fitted to the locomotive. I'm now using 100 degree solder as the thought of melting any of the joints doesn't bear thinking about. The results look OK. Not as curvy as I'd like but there isn't enough meat to grasp for filing. Even the small amount I carred out caused a ripple in the top which has had to be filed away.

Testing the Dock Tank

Dock Tank test
Originally uploaded by Phil_Parker.

There is a difference between running a model on a rolling road and giving it a spin on a real layout. With Melbridge Dock at Leamington Show I took it along to try out. I wanted to be sure that points and badly laid track wern't going to throw up problems.

Result - the thing works very nicely. Slightly better than my model in fact. And it hasn't been run in yet or had any weight put in the tanks. I suppose this is a combination of my greater experience putting chassis together and the jig that helped overcome my incompetence and lined everything up properly first time. It's an expensive toy but for the regular chassis builder a boon.

It was popular too. We showed the unfinished locomotive to many visitors which explaining how the models are built. Perhaps we always ought to keep a part built kit with us when we exhibit.

Boiler surgery

Boiler bottom
Originally uploaded by Phil_Parker.

With the main sections of the locomotive body together, I still faced a challenge. Put simply, bits of it were in the way of the mechanical parts. As usual the hole in the boiler wasn't big enough to allow the motor and gearbox in. Kit designers have to take a guess how much of a gap is required and this varies enormously. Some people will use a tiny motor that barely pokes above the frames at the cost of power. Others will stick in a two-stage 'box that pushes the motor well into the boiler. To make it worse, kits are often intended to be produced in several scales widening the possibilities.

The combination I am using should give plenty of power (this is a working model after all) and a sensible speed range. But it's too big for the supplied hole.

Making space is a horrible task involving a mini drill fitted with a cutting disk to cut across the boiler. Then making the cuts parallel to the sides with anything sharp I could lay my hands on including the slitting disk, scissors and side cutters. The result needs tidying up a bit but at least the body now fits.

Tanked up

Tanked up
Originally uploaded by Phil_Parker.

The side tanks are a nice origami exercise in brass. Most of the folds are square and easy to make. The curved area at the front was folded and the first flat area soldered Then the curve is made around a screwdriver and the rest fixed. Since the curve is hidden, absolute perfection isn't required - it's a pity those curves that do require it are often harder to get as good !

The beading along the top is supplied as etched lines with a half etched area to aid location. I found it a little fiddly as I'm not sure the location line is exactly right. Tack soldering and adjusting until you are happy is the key here. Then fix with lots of flux and very little solder, unless you enjoy cleaning off the excess that is.

Finally the tanks are fitted in place. Lots more tacking, measuring and adjusting here. The have to be upright and at 90 degrees to the footplate or the loco will look wrong. Getting this is harder than you'd expect as the eye is often deceived and only a square will do.

At this point the model looks a awful lot like a Jinty. I suppose they came out of the same design office for the same company so that isn't a surprise if you think about it. Standardisation was alive and well before BR discovered it !

Dock tank boiler

Dock tank boiler
Originally uploaded by Phil_Parker.

When I built my first dock tank, this was where it all went wrong. Mercian supply the boiler part rolled and in theory all you have to do is solder up the bottom and move on. When I tried it the result was an oval boiler and when I tried to fix this it ended up shaped like a 20p piece. At this point the thing was scrapped and replaced with some brass tube wrapped in plasticard to bring it up to the required diameter - this lead to a replacement firebox and smokebox 'cos you can solder the metal ones to plastic...

Anyway, this time the boiler rolling was finished up in my rolling bar thingies and once soldered is a joy to behold. The front and back supports which form the boxes went on quickly.

The smokebox took me two goes. There's a lot of lamination's to build up the front and I managed to get the wrapper slightly wrong. As it had only been tacked in place a quick heat allowed another go which went much better.

Best of all the boiler top appears to be parallel to the footplate. Always a relief !

Footplate fixed

Footplate fixed
Originally uploaded by Phil_Parker.

Attaching model locomotive bodies to chassis is a surprisingly contentious business. Obviously this matters - you want to pick up all the model, not just the top bits - but peoples preferences vary.

Some will argue for a clip fitting at one end and a single bolt at the other. Some prefer a multitude of tiny bolts (unavoidable with US prototypes which don't have a continuous footplate) while others, like me, want something chunky.

The kit is designed to go with the clip and single bolt method. Fine in theory, but the tabs in the footplate don't line up with the slots on the chassis. Altering either is difficult so I have put an extra hole on the chassis and used two decent sized (8BA) bolts. Anything smaller is a pain to fiddle with if you have to undo them. Besides, over engineering is always better than the alternative.

The footplate needs a little alteration before use. It's laminated and the brass top is more accurate than the nickle bottom. As it says in the instructions, the cut-out for the reversing gear needs to be opened up.

Soldering the nuts to the footplate was fun. At all costs you have to avoid fixing the bolt in place. I use combination of CD marker pen and WD40 to try and stop the solder running down the threads. This worked fine with the first bolt and failed on the second. Chopping an 8BA nut and bolt up with wire cutters didn't do them any favours either. I'm glad the third attempt went better.

Test running the chassis

Happy days - the dock tank chassis works. Balanced on my rolling road it's thrashing away like a good 'un. I expect that with all the joints in the waggly bits things will be a bit tight and some serious running in will be required. This will also show up any problems - in the middle section of the video the valve rod is moving up and down too much because the reversing link has become detached. Once re-soldered normal service was resumed.

The best news is that with the chassis working I can get on with the body. Our show is next week and I'd like to get enough done so I can test the model properly on a layout.