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pete_mcfarlane

Scratchbuilt LBSC I4 Atlantic tank

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Apart from a few wonky plasticard attempts when I was a teenager, I've never scratchbuilt a steam engine before so now seems to be a good time to try. I did consider building some wagons or a building for the Scratchuilding challenge, but came to the conclusion that this would defeat the whole point . So rather than repeating something I've done before, I'll have a go at pushing my skills a bit.

 

I've settled on the I4 class as a suitable prototype. These are a nice straightforward design - no splashers, very few curved parts and nice big side tanks to hold the motor and gearbox. There's a photo on one of these locos on wikipedia http://en.wikipedia.org/wiki/LB%26SCR_I2_class. Like a lot of Marsh's locos they were pretty hopeless, despite being superheated, and were gone by the end of the 1930s.

 

It just about fits in with my planned layout's location on the Kent/Sussex south coast border, as the real things were shedded at Brighton in the 1930s and had their cabs cut down to fit the SE section loading gauge.

 

It will be 4mm scale, 16.5mm gauge and painted in SR livery with a 4 digit number. There isn't a kit available, and I doubt if Bachmann will be doing one for a few years. I've yet to decide whether to build to body out of plasticard or nickel silver. This will depend on how well the chassis goes....

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Good luck with your build I am sure you will get all the help you need from the members here. Plus it is always nice to see another Southern loco being built.

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ISTR Hamilton Ellis described the I4 as "shocking engines", as you say, but that won't stop your model being a success. Good luck!

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Interesting locos, but the small boilers always made them look a bit anaemic IMHO - out of the four Atlantic tank classes only the I3s got it right.

 

Look forward to this Pete.

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Thanks for the positive comments.

 

Don't lose heart! You have plenty of time to accomplish this project.

That's the good thing about this year's challenge - we've got just over 6 months to do it.

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I've not yet started cutting metal, and won't for some time. But I've made the following progress.

 

I had a tidy of my railway books on Sunday and tracked dug out these two books:

post-1187-0-39289600-1332801537_thumb.jpg

I've had both of these for a while, but it's only now that I'm actually going to try building a loco. The Ahern book cost me £1.75 from a second hand bookshop on Watford High Street in the summer of 1995 when I was a student. The Guy Williams book was bought a few years later - my local library had a copy as a kid and I borrowed it many times.

 

I've also posted orders for some of the parts I'll need, including the motor and gearbox from Branchlines. I'm planning on using a big Mashima can motor and North Yard gearbox, along the lines of the mechanism in my J class tank engine. This is quiet, smooth and controllable - it does take up the lower part of the cab, but this isn't visible once the roof it on.

post-1187-0-92176100-1332801237_thumb.jpg

 

And as detailed here http://www.rmweb.co.uk/community/index.php?/blog/986/entry-9025-next-projects-modified-Hornby-e2-and-craftsman-t1/ I'm having a stab at building an etched loco kit for the first time, and finally finishing off my one and only attempt (so far) at a scratchbuilt chassis. Hopefully the experience should help me when I start.

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The Guy williams book is insperational nomater what scale you work in. I lost track of how many times I have read.

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I'm planning on using a big Mashima can motor and North Yard gearbox, along the lines of the mechanism in my J class tank engine. This is quiet, smooth and controllable - it does take up the lower part of the cab, but this isn't visible once the roof it on.

https://www.rmweb.co.uk/community/uploads/monthly_03_2012/post-1187-0-92176100-1332801237.jpg

 

I would have thought that the use of a rubber tube to turn the angle of the drive shaft a touch adds a dollop of resistance? Have a look at the CLAG website for their technique of introducing a ball-bearing in the tube to give it some flex points. http://www.clag.org.uk/silicone-tube.html

 

Also, have a look at the High Level site - http://chrisgibbon.com/webftp/Pages/ - for a whole range of gearbox/motor options that should not need to take up the cab. These go together very simply and run smoothly all the time. A trick I have learnt is go for the "+" versions (they have an additiona final drive that can be rotated). These have grub screw secured final gear wheels and thus are a little easier during the construction mode as you can get them on and off.

 

good luck.

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Yes and no. I now have a big pile of bits - some of the wheels (still waiting on the drivers), some tubing for the boiler and a pile of nickel silver sheet, strip etc. I've also tracked down some photos of I4s which I have on order from the Transport Treasury. I'm hoping to start construction in about a week or so, once the Craftsman T1 is ready for painting.

 

I'm still mulling over Portchullin Tatty's advice on gearboxes - I've not tried a High Level gearbox before, but they look interesting.

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Looking forward to following this, Pete. Another unusual choice to go along with the J and the T1.

 

David

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I had a bit more free time than I'd expected today, so I made a start on the I4. First of all I produced some rough sketches showing how it's going to fit together, where the fixing screws will go etc. This show shows the general mayhem on my kitchen table.

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Having got that far, I started cutting metal. It took two goes to get a decent footplate with straight edges..

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The footplate is 10 thou nickel silver, with 2mm square brass rod underneath to represent the valance. Buffer beams are from NS strip. I've decided that this will be number 2033, which had cutaway buffer beams, so these were carefully filed to shape once the beams were soldered in place. As per the advice in Guy Williams' book I've not yet cut the holes for the wheels and motor, leaving these until the footplate is a bit more rigid.

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I am pleased to see a start. I find it is always difficult for me to get motivated on a project until some metal or plastic is cut.

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This is the result of a weeks work.

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Most of the effort went in to the bits of the frame that project above the footplate. These took a while to shape correctly and get them at the right height. There are three parts of this model that I reckoned would be a bit tricky, and this was the first.

 

The second was the smokebox saddle, but that was surprisingly easy to do, although still I need to fit the curved sides (as I've no brass shim thin enough to curve to shape to hand). The third and last will be the chassis, as the profile of the frames has lots of changes of height, and should be fun to cut out. The blanks are in front of the superstructure, ready for marking out on Sunday.

 

Two more things are worth mentioning about the body. I used some 20mm brass tube from Eileen's Emporium for the boiler.And the slightly odd design of the cab and tanks on these locos means that they are being assembled round the boiler, with the cab removable (as the curved edges of the cab roof means that I can't make the roof removable).

 

The plan for the next week or so is to cut the frames out and assemble them.

 

I'm finding that scratchbuilding a loco in nickel silver is a lot easier than I expected, but a lot more time consuming. The biggest time killer is cutting out the parts, although that may get quicker as my metalwork skills improve.

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That is an impressive start. I sometimes when faced with a rounded roof, make the middle removeable, and use the gutters to hide the joins.

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That is an impressive start. I sometimes when faced with a rounded roof, make the middle removeable, and use the gutters to hide the joins.

I'd not thought of doing that. It won't work on the (Maunsell modified) I4 cab as the gutters don't extend to the edge of the roof. However I'll file it away for future reference.

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The last week has mostly been spent on the frames. The were slowly cut out of 15 thou nickel silver, with much swearing and braking of piercing saw blades, and the filed to shape. I made a plasticard template to ensure that they were the correct shape, but as the scribbling on it shows I got the bogie support wrong (this was corrected on the actual frames).

post-1187-0-37090300-1336946942_thumb.jpg

After taking this picture, the pilot holes were opened up with increasing large drill bits and then a reamer. I then fitted bearings, and soldered the frames together using a Comet frame assembly jig and their spacers. Some spare (slightly too small) Romford drivers were fitted, and amazingly it's all sqare and level.

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The openings for the bogie wheels is a weak point (the real frames have the massive section above the footplate to strengthen this section) so I've yet to fully cut them out. I'll do this when I have the bogie built and fitted, so I only remove the metal I need. There is a continous stip of frame spacers above the opening, to give some extra strength.

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And lastly, the body was perched on the chassis for a photo. The next week or so will be spent fitting the two together properly and adding detail to the chassis.

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It is coming on well. Do you know what motor and gearbox you are using yet? Also are going to use side control on the bogie, and radial. I always think it makes the loco run through curves so much better, less wriggling around.

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My current plan is to have the rear radial axle fixed and with no sideplay, with plenty of sideplay on the rear driver. In effect a 4-6-0, to try and avoid any tendency to waddle when running. Drive will need to be to the front coupled axle, and I've still not picked a gearbox. The bogie will probably need some kind of springing as you suggest.

 

Of course, Mr Marsh would turn in his grave at the thought of one of his locomotives having a fixed trailing axle. Such things can only lead to disaster.

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Not much happened last week - but the last few days have seen a burst of activity on the bodywork, which now looks like this.

post-1187-0-85015800-1337727860_thumb.jpg

The tanks were relatively straightforward to make. I cut a strip of metal to the correct height, put the nend in it and then cut and filed to shape It took a while to get the cut outs for the boilers in the tank front right.

 

The bunker also needed a bit of trial and error to get the second bend in the right place. It doesn't show where it was straightened out and bent again! One advantage of living on your own is that nobody can object to you annealing bits of nickel silver on the cooker....

 

I'm half way through fitting the tops of the side tanks, and then there's the cab. It is starting to look like an I4 - they have a massive top heavy look to them due to the high pitched superheated boiler.

 

A trip to Mr Humm's most excellent transport bookshop in Stamford the other week lead to me buying a copy of "The Locomotives of D.E.Marsh" by Charles Fryer, which gives some more information on the convoluted saga of the I1, I2 and I4 classes. I did wonder what had happened if these locos had been built before the first superheated I3, as seems to have been the original plan. The Brighton's first superheated locos would have been the useless I4s, rather than the spectacularly successful I3, and loco development in this country would have turned out very differently.

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Seems to be coming along a treat. The side tanks came out alright.

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.

A trip to Mr Humm's most excellent transport bookshop in Stamford the other week lead to me buying a copy of "The Locomotives of D.E.Marsh" by Charles Fryer, which gives some more information on the convoluted saga of the I1, I2 and I4 classes.

 

A bit OT Pete, but does it shed any light on the origin for the less-than-complimentary nickname given to the I1s (the one that rhymes with bankers)?

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Seems to be coming along a treat. The side tanks came out alright.

After I'd carefully unsoldered the left hand one and eased it out a bit, they are now nice and square.

A bit OT Pete, but does it shed any light on the origin for the less-than-complimentary nickname given to the I1s (the one that rhymes with bankers)?

Sadly not. I'm also intruiged by that nickname. It seems to have been used for several other less than successful loco types, including the LSWR T14s.

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Progress has slowed a little, mainly due to my modelling time being spent on my T1 and E2, but I do now have a motor and gearbox. A small Mashima 1020 and matching Comet 38:1 gearbox driving the front axle.

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This projects a little in to the cab, but this will be hidden by the backhead and side sheets.

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Some of the details have also been added - beading along the tank tops (brass L section on top of the side sheets), buffers and some of the handrails. I'm still waiting for wheels.

 

The new major task is the cab. I've also sent off an order to SEF for some I3 spares - a raid on the spare box turned up a suitable chimney and dome which I think were leftover from my DJH C2x.

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