Coal rails on LNWR Tank Engines

[justin]

Can anyone tell me, or provide photos or drawings, of what happens to the coal rails fitted to the bunkers of various Webb 2-4-2 and 0-6-2T locos at the point where the bunker rises up at the back. Were they continuous across the inside of the back of the bunker or did they stop at the edge of the bunker as it increased in height at the back. Below is a photo of the preserved coal tank which hopefully demonstrates the area I'm interested in. The top rail on this loco does appear to stop rather than carry across. I really want to know about the arrangement on the 5'6" 2-4-2T locos but general information is welcome.

 

 

[Michael Edge]

This is the best close up I can find of a 5'6" 2-4-2T.

I would suggest that the ends of the coal rails are flattened to fix on the inside of the bunker back.

[Nick Holliday]

I did find this rather blurry view, part of an H C Casserley photo taken in Crewe steelworks in 1947, showing the remains of coal tank bunkers. It comes from the excellent monograph on the Coal Tanks, "Bashers, Gadgets and Mourners"

 

I would say it suggests that the coal rails are continuous, although that is only a vague impression.

However, as purely circumstantial evidence, I would make the following suggestions:

• A continuous rail, formed into a U shape out of a single length of 2" diameter piping, would have considerably greater strength/resistance to bending than shorter L bars, reliant on fixings to the bunker plate.
• The amount of work to cut shorter bars, bend to an L and flatten them would be considerably more than a single U bar, with little saving in materials costs.
• Fixing individual pieces would be more labour intensive.
• There is no evidence of any fixings within the curved top panel of the bunker rear, which  would be required if the rails were cut short, and visible, as welding was not an option.
• More coal would be trapped behind the tank filler - a problem which anyway caused severe rusting on the reserved loco.

This does assume that 2" pipes will fit between the tank filler and the bunker rear, but it looks as if there is enough room to do so.

 

 

 

[jim.snowdon]

4 hours ago, Nick Holliday said:

A continuous rail, formed into a U shape out of a single length of 2" diameter piping, would have considerably greater strength/resistance to bending than shorter L bars, reliant on fixings to the bunker plate.

As far as I am aware, the common material for coal rails generally was a 'squashed' D section, with the inside (flat) surface riveted to vertical brackets manufactured from flat strip section.

 

4 hours ago, Nick Holliday said:

There is no evidence of any fixings within the curved top panel of the bunker rear, which  would be required if the rails were cut short, and visible, as welding was not an option.

Looking closely at the pictures, there is an upright support from the coal rails behind the start of the curved panel. This is just visible on the top rail and becomes hidden as it passes behind the 2nd coal rail, counting downwards.

 

[Nick Holliday]

18 hours ago, jim.snowdon said:

As far as I am aware, the common material for coal rails generally was a 'squashed' D section, with the inside (flat) surface riveted to vertical brackets manufactured from flat strip section.

Could well be the case.  I was just making assumptions based on the rather poorly reproduced tender drawings in Talbot's book on LNWR Locos. Presumably that would use a solid half-round bar. Most other lines seem to have used a square section - the LNWR rounded face is a better aesthetic, but was it any stronger?

I was also mislead by Jack Nelson, the doyen of the LNWR, and his isometric view of a Coal Tank, although I could tell he had got it wrong with regard to the placing of the coal rails outside the curved bunker plate, and a vague suggestion of a full round section.

Unfortunately photos showing the inside of bunkers, even on tender locos, are extremely rare - the best I found was useless for this task, as it showed a tender fitted with tanks for oil burning trials, with any rails removed! 

This view of a Coal Tank was the best I could find, and I am not entirely convinced one way or the other, as the rails on the far side look pretty full bodied.

18 hours ago, jim.snowdon said:

Looking closely at the pictures, there is an upright support from the coal rails behind the start of the curved panel. This is just visible on the top rail and becomes hidden as it passes behind the 2nd coal rail, counting downwards.

 

 

I agree there had to be a vertical support at the corner - what I was discussing was, if each rail was split, each would require some fixings, perhaps as I have crudely noted in green. I appreciate that Victorian and Edwardian loco builders would have made sure that such fixings would be invisible when first built, but there doesn't appear to be any corresponding signs in later years when rusting would be more visible. It looks to me as if there was a single central vertical support by the tank filler, as there seems to be a slight gap between the rails and the curved bunker plate.

Perhaps the OP should contact the custodians of No 1054 for their, hopefully definitive, answer.

[justin]

Thanks for everyone's input. It does seem to be a tricky one. I have recently joined the LNWR Society and have remembered they also have a forum for questions. At present I'm waiting for approval of my login to use the forum. If there is a definitive answer I'l pass it on. Otherwise I think contacting the Bahamas Society is a good idea. In the meantime if anyone else does have the answer feel free to contribute.

 

Its amazing how once you start a model you realise there are all sorts areas where details are very unclear. 

[jim.snowdon]

5 hours ago, Nick Holliday said:

I agree there had to be a vertical support at the corner - what I was discussing was, if each rail was split, each would require some fixings, perhaps as I have crudely noted in green. I appreciate that Victorian and Edwardian loco builders would have made sure that such fixings would be invisible when first built, but there doesn't appear to be any corresponding signs in later years when rusting would be more visible. It looks to me as if there was a single central vertical support by the tank filler, as there seems to be a slight gap between the rails and the curved bunker plate.

Perhaps the OP should contact the custodians of No 1054 for their, hopefully definitive, answer.

If you look carefully at the picture of the Coal tank, part of which I have cut out -

 

 

you will see that there are, in the top rail, two pairs of rivets either side of the centreline, close(ish) to the water filler. It is also evident that a little way inboard of those rivets, the rail stops abruptly in a squared off end. It clearly isn't continuous across the full with of the bunker. On the next rail down, there is a further rivet visible on each side, below those in the top rai, which would suggest that the rails are not fastened to the inside of the raised centre section of the bunker back plate, but separate and supported by a vertical bar, which will doubtless be riveted to the top of the tank. The coal rails are neither continuous nor attached to the bunk plate.

 

 

[Michael Edge]

What the preserved loco looks like now isn't going to prove this one way or the other.

[jim.snowdon]

Since it had coal rails when it went into preservation, its current state will almost certainly mirror the state in which it came out of service because any replacement parts will have been made using the originals as patterns.

Besides, splitting the coal rails into left and right halves and attaching them with brackets riveted to the tank top makes more engineering sense than either making them continuous or riveting them to the bunker backplate.