MHR Restorations and Overhauls

Just how many 'friends groups' do we need & is there the stomach for them?.......

BTW - hows the lines 'forgotten' loco - 75079 coming on?..... there hasn't been a blog for ages & surely that is a loco deserving of support in the short term to get her into traffic?..... 80150 & 34058 are but pipe dreams at the mo, though in the case of the latter, it wouldn't take long to put her back together given the kit of parts that arrived with her......

 

Went in there a bit earlier Dave for a couple of hours, and it *looked* like it's really coming along with the boiler cladding back on. But I don't recall seeing a post anywhere saying that the boiler has a) been out of the frames or b) been steamed yet? A blog would be most welcome. I'm sure it will be a popular locomotive when she is eventually outshopped.

James

 

the boiler hasnt been touched yet, the claddings being fitted just to ensure that once the boiler is done it is ready to go on, with the minimum of messing around , at least that was the answer i got last time i asked that question

 

Thanks for clarifying

James

 

thats what i was told, does anyone in the know, know what condition the boiler is in? is the boiler on a standard 4, 4-6-0, the same as the 4 tank ?

 

I remember enquiring years ago about the boiler condition when the loco was at the Plym Valley Railway. I think it is pretty sound but may require a new tubeplate in the firebox as far as I can remember.

 

We will find out in due course I suppose. Because of the construction of standard locos it makes sense to finish just about everything before starting on the boiler because almost everything is hung off the boiler.

 

All you need to know about BR 4 and 5 boilers

The 75xxx class had BR4 pattern boilers, and 80xxx tanks were fitted with BR5 pattern boiler.

The BR4 were very similar design to the BR5, the main differences being:

BR4 Boiler pressure BR4 225psi / BR5 200psi

Firebox staying was differed on each boiler type due to the differing pressures.

BR4 boiler is physically longer (9 inches) and therefore cannot be fitted to a BR std cl. 4 2-6-4 tank (or any other BR std design)

BR4 type manufactured total 88 - 80 locomotive (75000-75079) and 8 spares - 10% of class as works exchange units.
6 BR4 pattern boilers exist today (6.75% of type constructed)

BR5 type manufactured total 162 - 155 locomotive (80000 - 80154) and 7 spares - 4.5% of the class as works exchange units.
15 BR5 pattern boilers exist today (9.25% of type constructed)

BR4 boiler was found to be less efficient/successful than the BR5 type (initially at least) , its slightly bigger size did not produce the desired steaming rates required in traffic, as the the drafting/grate size ratio etc were the same between both types the logical step taken was to develop the double blast pipe to increase the steaming rate.

75014 and 75027 retain the single blastpipe 75029, 75069, 75078, 75079 modified to double by BR. All BR5s have single blastpipe design.

 

You'd better tell all 80XXX owners to reduce their boiler pressure from 225 psi, then!

 

how does the mogul boiler compare? (76017)

 

The original design (based upon the LMS 4C pattern) was rated at 200psi. BR updated the design to 225psi

 

The LMS Ivatt 4mt 2-6-0 had a 4D pattern boiler which BR based the BR7 boiler that was used on the BR std cl 4mt 2-6-0 76xxx class

122 built (115 locomotive and 7 spares)

Unlike the LMS version the BR7 pattern was successful out of the gate (the LMS version had drafting/steaming issues which included fitting/removing double chimney-blastpipes)

 

The only difference between BR4 and BR5 boilers is that the BR4 is 9" longer than a BR5. Where has the nonsense about different boiler pressures and stay patterns come from?

 

I think I'm right in saying that the major boiler/fireboxcomponents are common (i.e. backhead, throatplate, tubeplate ec. and that the NYMR has formers for all of them for use with its fleet of 4MT locos (75029/76079/80135/6).

 

76079's boiler and firebox are dimensionally different to the other locos.

 

Why would that be?

 

Because 76079's boiler was similar to the boiler of the Ivatt 4, using the same flanging blocks. The boilers for the Class 4 4-6-0s and 2-6-4 tanks were similar to the boilers on the Stanier and Fairburn 2-6-4 tanks, using their flanging blocks, but the stay pattern was different to take into account the increased psi

 

Ok so not all the Standards were that Standard then?

 

Probably more so than the Black 5's.

 

can we have a separate thread for restoration projects at the MHR?