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Post by insvorloc on Jul 23, 2012 2:00:29 GMT
Hello:
I plan on building the 5" gauge large Prairie tank locomotive to Trevor Shortland's design from castings sold by Reeves,
I have a well equipped shop, and have built a live steam tender locomotive - but never a "tank" locomotive. I need some down-to-earth advice on this grandiose plan. Here are my questions:
1. Do tank locomotives present any particular building challenges with respect to the metalwork for the tank-boiler
combination? I plan on buying the full casting set including the boiler kit from Reeves.
2. Does the Reeves boiler kit include the parts for the tank?
3. Is anything inherently complex about the machining of the
locomotive castings - any particular parts or systems that have proven "horrific".
4. How is the cylinder block to machine? At a cost of 615 Pounds, I don't want to "mess up".
5. Are the plans "user-friendly"? Is everything you need to know shown clearly in the plans?
6. Do the axles or crankpins or anything else on the locomotive need to be hardened and ground?
Any insights, experiences or "reality-check" advice would be most appreciated.
Thank you.
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Post by alanstepney on Jul 23, 2012 8:27:03 GMT
I'll jump in here, but with the proviso that I have only glanced at that specifc design, so am not fully conversant with it.
1. No. Just treat the tanks like any other unit, and build as carefully as you would anything else.
PS, make sure the joints are water-tight before fitting to engine.
2.No.
3. I'm not aware of any special "horrors".
4. Needs LOTS of care, plus measure, measure, measure, then check measurements.
Then check again. And again.
Take you time ove rit, and all will be well.
5. I doubt the plans are error-free. Hardly any of them are.
Check each part that you make to ensure that it matches up to its mating part, before you cut metal.
6. No.
Others here may be able to add more, or have diferent views.
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Post by Rex Hanman on Jul 23, 2012 9:45:42 GMT
The design is not for the faint hearted, the drawings are very detailed. Don't let that put you off though.  Where are you located?  You are welcome to come and peruse my drawings if you are anywhere near Hampshire/Wiltshire.  |
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Post by Laurie_B on Jul 23, 2012 9:49:04 GMT
Hello, I'm building a 5" gauge 5101 class to the Trevor Shortland/Reeves design.I bought an abandoned project a while ago so some of the work had been done. I suppose the only comments regarding the tanks is that they have an awful lot of rivets in them,otherwise they are as Alan S says,but bear in mind alanetm's posting about the drawings only showing the left hand tank and making no reference for provision for the reach rod in the right hand tank.I don't think Reeves do sheet metal parts for the tank. The cylinder block is as full size practice.The block I inherited had been machined fairly basically.I should imagine it needs carefully marking out-well more than usual! The drawings (agree with Alan S) they do contain errors as I and others have found.Apparently Reeves redrew the Shortland design and I suspect errors have crept in as a result. I'm not aware of any parts that need to be ground finish.Trevor Shortland/Reeves specify EN8 for the axles.This can be obtained from GLR Supplies and is lovely stuff to machine.Well,I thought so! As my loco had the frames done already,I didn't have to form the joggles in the frames ahead of the radial truck.These could be a problem,maybe other builders could advise? The radial truck,I found was not the easiest item to set up to machine the curved surfaces,or the truck horn guides. As the design is based closely on Swindon drawings it is quite complex,but I have found it a very satisfying project-so far anyway! Attached is a photo of the underside of the pony truck I completed recently,showing the EN8 axle before fitting the keeps.There are quite a lot of parts in this assembly alone! Attachments:
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Post by insvorloc on Jul 24, 2012 3:15:06 GMT
Thank you for the very useful information. Rex, thanks for the invitation, but I am
across the Atlantic - however, I appreciate the gesture.
A few more questions:
1. The cylinder block - the bore is listed as 1.625". What is the depth
of the the cylinder block bore, i.e. how deep will I have to bore the 1.625" diameter?
2. The price of the cylinder block is 615 Pounds. What is there about the castings
that make them so expensive?
3. Are there any UK suppliers that build boilers for the 5" gauge Prairie?
Anybody have an idea of the price for one?
4. Does anyone sell a "wheel flange profiling tool?" It is a tool-bit that you
mount in your lathe toolpost, and bring into contact with the unfinished
wheel, and it profiles the flange and tread to the established standard.
I would need one for 5" gauge wheels.
Thank you.
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Post by Rex Hanman on Jul 24, 2012 8:37:03 GMT
The cylinder block casting is complex and detailed but to be honest I can't see how they justify £615, lack of competition I guess! The boring goes all the way through and a glance at the drawing shows that to be 3 3/8", however, the bores for the piston valve liners are shown as 1.0625" for 4 15/32" from front to back. I am sure any reputable boiler maker would build the boiler but I have no idea of cost other than "expensive"! I don't know of any supplier of a wheel profiling tool. Shame you are so far away, but if you need any more info I am sure we can help.  |
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Post by Laurie_B on Jul 24, 2012 10:27:37 GMT
1) As Rex says,the cylinder has a plain bore from front to back.The cylinder bores are also lined.The castings for these are quite expensive too,I machined mine from solid bar which was a lot cheaper,but made for a lot of swarf!
2) The cylinder castings are expensive as the are based on works drawings (e.g. they have the steam and exhaust passageways cast in),and Reeves do run a business after all.
3) Agree with Rex that most boiler makers could build you a boiler.Prices could range from £2,500 up to £4,000.Most boiler makers have quite long lead times if their order books aren't already full.
4) I think there is a 'button' form tool available for machining the wheel profile root radius.For the flange radius,I use a file.
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Post by insvorloc on Jul 25, 2012 5:05:56 GMT
I made some queries about boilers, and received the following response from one vendor:
"I do not offer the Prairie boiler to the Shortland design as the outer fire box is not the correct GWR shape. I can however offer you a correct shape GWR No2 boiler that wil fit the shortland chassis and smoke box."
I don't have Trevor Shortland's plans, and I was unable to determine anything from the book
by Brian Whitehurst with reference to the above comment. Does anybody know what this comment refers to?
What is the correct shape for the Prairie boiler?
Thank you.
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Post by Laurie_B on Jul 26, 2012 9:44:58 GMT
The vendor you mention might be right.I don't have a detailed drawing of the Swindon No.2 boiler to compare with the Reeves/Shortland design.But comparing this to the GWR "Frame Plan" for the 5101 class,the boiler doesn't look that bad.
Even if the boiler isn't exactly to scale then as long as the boiler cladding is to scale then it won't matter.There have been a few of these model locos built (including one built by Trevor Shortland himself) and they look about right.
Perhaps some comments by Mr.Dave Aitken in his article "Great Western Workshop" (E.I.M. May 2002/Vol 23 No.11.) may help.Mr Aitken writes:
"Reeves 5" gauge model is probably the most highly detailed and accurate Great Western locomotive model available"
"Those designs which are available range from the highly detailed and extremely accurate - like the Reeves 51xx Prairie tank loco......."
He goes on to mention that Reeves' 7-1/4" gauge GWR 'Mogul' has an oversize boiler,which implies that the model 51xx boiler could be reasonably accurate.
I haven't got as far as the boiler yet-I just hope Mr Aitken is right!
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jma1009
Elder Statesman
Posts: 5,900
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Post by jma1009 on Jul 30, 2012 8:54:22 GMT
i wouldnt say the Trevor Shortland PRAIREE is that wonderful.
the backhead is awful as are some of the fittings and layout and nothing like fullsize. also the boiler is relatively small for such a big loco. ok it's more detailed than Martin Evan's 5"g FIREFLY PRAIREE tank, but i wouldnt go much further than that!
cheers,
julian
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You are welcome to come and peruse my drawings if you are anywhere near Hampshire/Wiltshire. 
