Bulleid Pacifics - Past or Present

With 35010 making a rare appearance on this thread, does anyone else own a copy of Bradford Barton's Southern Steam locomotice survey - Bulleid Merchant Navy Pacifics? For the benefit of anyone who does not, the book ends on a happy note, with shots of 35028 in preservation times, but the penultimate page features 35010 at Barry, taken when its rescue seemed highly unlikely. The caption accompanying the picture is very poignant and worth quoting in full - especially as the future has turned out to be somewhat kinder for 35010 than the author could have anticipated:-

Hundreds of men helped to build you; hundreds more maintained you and worked on your footplate. They hated you, cursed you, loved you and will remember you with affection. Many footplatemen from Exmouth Junction, Salisbury, Nine Elms, Bournemouth, Eastleigh, Stewarts Lane and Dover found fame at your regulator and became the heroes of the railway press. Many more made equally wonderful runs and remained unsung, but are remembered by their colleagues for the prowess, fully deserving the simple epithet of being "good enginemen". They knew, through, long experience, how to make you pick up your heels and go, when lesser mortals could not handle such mettlesome mounts as you and your twenty-nine stable companions. Once you could run at 100 mph or pull 600 tons, Now you are no longer No. 35010 Blue Star but just so much rusting scrap metal in Woodham Bros' Yard in alien South Wales. This is not the "Merchant Navy" we knew and as for so many of those who worked on you, retirement has come, and for you it could have been with more dignity.

A bit of poetic license here, I think for, to my knowledge, 35010 was never an Eastern Section engine and although a strong engine, not one of the fastest so probably never hit 100 mph, but still quite a moving tribute to an engine which the author never expected to turn its wheels again.

 

The recent appeal hopes to raise £15,000 which is the estimated cost of replacing the right hand cylinder and start the restoration of 35010 without diverting funds from the black five. http://www.besps.org/Newsletter01.htm
Hopefully this can be done for cheaper, it's nice to see that they still care about their other locomotive and it's not left to rot away like some other bulleid locomotives.

 

I thought the 15K was for a risky repair to it? - this before the advent of 3D printed patterns and moulds. With EPS and 3D printed moulds, a new cylinder would be better, and within the 15K budget..

 

The news about the colne valley not closing as well will be a boost


Sent from my iPhone using Tapatalk

 

Looking on the MHR web site I see there is now a web page asking people to sponsor a stay for 35005.


http://preservation.watercressline.co.uk/blog/entry/sponsor-a-stay-update


Anyone going to sponsor a stay?

 

A grouping of Bulleids for the SVR SSG with 34081 visiting to join 34053 and 34027.
http://www.svr.co.uk/SEItem.aspx?a=65

 

Oh no! At least 3 Pacifics at the so called 'small engine' gala'! (Tongue very firmly in cheek) Dosn't look like a bad line up so far. Nice one SVR

 

*fingers crossed* 847........please!

Chris

 

On the 35018 thread

What seems odd to me is that even a light pacific has a very short chimney, implying that the top of the boiler is close to the loading gauge. Is the boiler diameter almost the same on both classes, is it mounted slightly higher on the light pacifics, or what?

 

I believe they were kept to the same total height as the originals, which were flush with the roof. However, the original chimneys were located at a point where the fabricated smokebox roof sloped down into the front cowling to aid smoke deflection.

As a P2-style smokebox would have been required if this feature was retained in the rebuilding process, the new chimney was the best that could be achieved with the standard cylindrical smokebox adopted.

 

There is an optimum length for a chimney and the larger the diameter of the smokebox, more of the chimney is inside it and thus no need for a long chimney protruding out of the smokebox.

 

Bit of yes, bit of no. The front of the boiler barrel and the smokebox are smaller diameter on a light pacific. However, the rear of the barrel where it enters the firebox is the same diameter for both classes, and the firebox is essentially the same profile on both, just longer for an MN (and therefore deeper at the front with the sloping grate). The peculiarity is that both types of boilers have the taper on the underside, so the top of the boiler is horizontal; this is in contrast to just about every other taper boiler in this country, which were usually straight cones or horizontal underneath.

So if you use your image search engine of choice and look for good head on photos of (for instance) 34046 and 35028, you'll see that for 35028 the underside of the smokebox makes a near perfect tangent with the level of the foot plating either side, whereas for 34046 the underside of the smokebox is several inches clear. As a result, the chimney height is much the same.

 

The underside taper to the Bulleid boiler barrel is one of the design features that makes these boilers easier to maintain than almost everything else. For when washing out the boiler barrel, the sludge (not scale, we all use decent water treatment regimes don't we??) is naturally carried by the washing water from the front to back of the barrel, then onto the ground via the firebox.

The U channel is another excellent bit of design, when washing out the water carries the sludge efficiently away. In a foundation ring boiler, the flat bottom means the water runs away leaving sludge behind.

 

Are you? do tell.

 

Only on a WC/BB as the Merchant Navy boilers have a traditional foundation ring!

 

True. You only have to look at photos of 35005 being stripped down to see that it has a traditional flat-bottomed foundation ring.

 

I think that was a weight-saving measure. For a given water level, if the boiler tapers on the bottom, you disproportionately lose water volume rather than steam volume. So the overall boiler weight in working order will be lower than for an equivalent amount of taper on the top side, or equally distributed between top and bottom. One impact is you end up with very squat boiler fittings to remain within gauge.

There was also a difference, I believe, between the first five (or possibly ten) MN boilers and all the subsequent ones. On those initial boilers, the ring adjacent to the firebox was parallel, and that adjacent to the smokebox was tapered on its lower side. After the first boilers, the taper was put on the ring adjacent to the firebox, with the ring adjacent to the smokebox being parallel (and of reduced diameter). The effect was again a weight saving in both material and stored water, without having any impact on heating surface. The first five boilers were interchangeable with the others and in time were distributed across the fleet as a result of normal boiler exchanges at overhaul.

This photo just about shows the taper on the ring adjacent to the firebox; note how the bottom plate is not parallel to the tubes on that ring, but is parallel to the tubes on the front ring.



Tom

 

I did always wonder about about that (it was the first ten, BTW), because I'd assumed that the first ten locos would have had to have additional frame lightening to accommodate the heavier boilers, so they could take later boilers but not vice versa. However, a quick look at the records shows I was wrong and the boilers certainly did get around. Three of the 'survivors' demonstrate this: 35009 and 35010 have late pattern boilers, while 35011 has an early pattern.

 

I've sponsored two

 

I thought the essential rationale for tapering a boiler along the top was to have plenty of steam space at the firebox end, where the boiling is most furious, and less near the smokebox. What's the advantage of a boiler tapered along the bottom over one of smaller diameter all the way?