How to spot superheaters?

[Harlequin]

I've been reading through Russell "... Great Western Engines" Vol. 2 and I've noticed that the text often implies that the presence of a superheater on a loco is obvious from the photos (and to some extent from the drawings).

 

Not obvious to me! I know what a superheater is and where it is so I'm looking for details around the rear of the smokebox. Sometimes there are a few rivet heads visible but I don't think their presence always correlates with the presence of a superheater.

 

Sometimes there are helpfully two photos of the same class on the same page, one superheated, the other not, but I still can't see what the difference is!

 

What are the tell-tale signs of superheating in photos? What am I missing?

 

[Neal Ball]

Isn't it this? The "pipework" under the handrail on this side?

[JimC]

No, that's the 4 cone ejector. 

[franciswilliamwebb]

 

The blister circled above (sizes and shapes can vary) is often used as the spotting feature for superheated GWR locos.  It isn't actually the superheater itself, just the cover for ancillary equipment.

Edited February 27, 2023 by franciswilliamwebb
(made it more grammarer)

[Harlequin]

As I understand it, blisters like that cover the hydrostatic lubrication pipes where they emerge from under the lagging and connect into the smokebox. Is that always associated with a superheater?

 

Most of the photos and drawings in the book show the left hand side of the locos. Is there a way to tell from the left hand side?

 

Edited February 27, 2023 by Harlequin

[Happy Hippo]

14 minutes ago, franciswilliamwebb said:

 

The blister circled above (sizes and shapes can vary) is often used as the spotting feature for superheated GWR locos.  It isn't actually the superheater itself, just the cover for ancillary equipment.

As Phil points out the bulged cover plate is for the oil feeds. The oil feed pipes under the boiler cladding needed to be lifted clear of the join where the boiler cladding met the smokebox ring.  The cover was removeable to give access for inspection and maintanence when required. 

 

A superheater is just a series of pipes that carries steam from the regulator back down through the enlarged superheater tubes in the boiler. The tubes may go back and forth several times before being delivered to the  steam chests and thence to the cylinders.

 

Most GW loco had hydrostatic lubricators whereby oil was introduced into the steam to lubricate the  steam valves.  

 

When the change to a higher superheat was made to certain locos, the hydrostatic lubricator was not as effective, so a change to mechanical lubricators was made.

 

This resulted in a change to the piping arrangements on the rhs of the boiler, which created the larger and more obvious covered plate as shown in the picture.

 

[This is a very simplistic explanation.]

 

 

 

 

[The Stationmaster]

The simple way to identify an ex GWR loco with high temperature superheat is the presence of.a mechanical lubricator alomgsoide the smokebox plus, sometimes. a different style of 'blister' for the pipework as mentioned by 'Happy Hippo'.  

 

But the simplest way of all to establish if a GW engine is superheated is to open the smokebox door (although obviously rarely a practical proposition).  

[Neal Ball]

27 minutes ago, The Stationmaster said:

.....the simplest way of all to establish if a GW engine is superheated is to open the smokebox door (although obviously rarely a practical proposition).  

 

Silly thing was that I could describe exactly what its like when you open the smokebox, but a different matter on the outside of the actual loco.

 

Thanks all for the prompts.

[JimC]

2 hours ago, Happy Hippo said:

As Phil points out the bulged cover plate is for the oil feeds. The oil feed pipes under the boiler cladding needed to be lifted clear of the join where the boiler cladding met the smokebox ring.  The cover was removeable to give access for inspection and maintanence when required. 

 

A superheater is just a series of pipes that carries steam from the regulator back down through the enlarged superheater tubes in the boiler. The tubes may go back and forth several times before being delivered to the  steam chests and thence to the cylinders.

 

Most GW loco had hydrostatic lubricators whereby oil was introduced into the steam to lubricate the  steam valves.  

 

When the change to a higher superheat was made to certain locos, the hydrostatic lubricator was not as effective, so a change to mechanical lubricators was made.

 

This resulted in a change to the piping arrangements on the rhs of the boiler, which created the larger and more obvious covered plate as shown in the picture.

 

[This is a very simplistic explanation.]

 

 

 

 

Trouble is there are also oil feeds on the saturated types, if not as many. I'm glad I'm not the only person who's wondered what on earth it is that is visible. Pre group and 94xx panniers are the ones where I'd very much like to be able to tell and haven't managed to.work out a way. 

[Happy Hippo]

The first 10 of the 94xx panniers were superheated. The rest, plus the 84xx and 34 xx classes were not.

 

A quick flick through the appropriate 'Pannier Papers' shows an oil feed pipe cover fitted close to the the top of where the rhs tank and smokebox meet, on both the superheated and non superheated locos.

 

I would imagine that most if not all pre grouping panniers would not have been superheated, and the piping cover would have been dependent on whether the pannier tank was 'flat topped' similar to the later 64/74xx or 57xx style of loco with a profiled top.

Edited February 27, 2023 by Happy Hippo

[JimC]

3 minutes ago, Happy Hippo said:

The first 10 of the 94xx panniers were superheated. The rest, plus the 84xx and 34 xx classes were not.

That's how they were built, yes. Did they stay like that? I've seen it said 9400 no longer has a superheated boiler.

 

IIRC according to RCTS only enough saturated Std 10s were built to fit the 15s and the 94s with none spare for a pool. There must have been superheated Std 10s reasonably available from the pool for 2251s and absorbed, plus more freed up as absorbed locomotives were withdrawn while the 94s were being built. Were s/H superheated boilers retubed? RCTS doesn't mention it AFAICS, and it does for other types. Were the 10 superheated locomotives allocated separately? Did superheated boilers migrate round the fleet? I haven't managed to find any of this out. I must get to Kew and look at boiler records to see if there are any clues. 

[Happy Hippo]

The boiler on 9400 was swapped out for a non superheated boiler in 1955 according to Preserved British Steam Locomotives .com

 

https://preservedbritishsteamlocomotives.com/9400-2/

 

If you look at the picture of 9400 at Swindon being prepared for preservation, the position of the oil feed pipes is very clear as all the cladding is off the boiler and pannier tanks.

 

As I mentioned in my earlier post,  all the pictures in the relevant 'Pannier Papers' which are taken from GWR through to late BR(W) steam show no changes to the external profile of the tank smokebox or pipe feed cover so it is impossible to tell whether the loco was superheated or not superheated unless you were to stick your head inside the smokebox.

 

Since the boiler overhaul regime was on a different schedule to a loco going through the works, I would suggest that if the boiler was appropriate for the loco, it came off the front of the line of available boilers.

 

As you are aware, as far as Swindon was concerned, Locos went in for overhaul and at that point there were components that became  pool items, so a standard 10 boiler could migrate around the fleet:  Effectively the overhauled boilers went out on a first come first served basis providing they were suitable.  I would suggest that the only time an S10 superheated boiler  would be specified would be if it were for a 2251 class loco.  The 15xx and 34/84/94 xx being shunting or local freight locos had no urgent requirement to be superheated.

 

One of the best pictures I have seen of the Swindon approach to outshopping locos on a first come first served basis, is of 6630 with a smokebox fitted, which had obviously come from a loco that had been fitted with outside steam pipes. This was a more common occurrence with the 28/38xx or the 42/5202/72xx fleets where the steam admission route to the piston valves had  been changed.

 

As far as rebuilding a superheated boiler into a non superheated boiler is concerned my take on that is certainly not.

 

Simply re-tubing a boiler is time consuming, and if one had to re-tube it from superheated to the non superheated version, the boiler would require new front and back end plates so that the required number of tubes could be fitted. The superheater boiler having fewer tubes, but  some of these are of a much larger diameter in order to accommodate the superheater elements.  When you consider that one of those end plates is a part of the firebox, the work involved in the rebuild is significantly increased. 

 

As someone who has worked on boilers in the past, I'd say that once you have to carry out serious modifications such as these, it would be easier and quicker and probably cheaper to build a new boiler to the specification you require.

Edited February 27, 2023 by Happy Hippo
rebuilding a superheated boiler

[JimC]

2 hours ago, Happy Hippo said:

 

Since the boiler overhaul regime was on a different schedule to a loco going through the works, I would suggest that if the boiler was appropriate for the loco, it came off the front of the line of available boilers.

Indeed, but according to the numbers in RCTS there weren't any spare non-super Std 10s to form a pool for the 94s and 15s.

 

Rcts records various boilers being converted between superheated and not in the first quarter of 20thC, but not Std 10s. As you say a very big job, but they did have all the facilities. 

 

So it appears to me we are left with 4 possibilities

1.superheated boilers were fitted on externally built 94s, with or maybe even without the actual superheater elements and header. 

2. Some super-standard 10s were rebuilt without flue tubes and used for a pool, even though RCTS doesn't mention it. 

3. RCTS has got the total of non-super Std 10s built wrong. 

4. There was no boiler pool for the non super Std 10s.

 

None of these seem especially likely! 

[Harlequin]

Here's an example from Russell:

 

On page 80 of Vol. 2 he shows two line drawings of the left hand side of two Star class locos and he says:

 

Quote

In Figure 197, North Star is seen as built in 1906, with the 4-4-2 classification and not superheated. In the lower drawing, Figure 198, the class is now 4-6-0 and this shows No. 4021 fitted with No. 3 superheater and curved framing.

 

So he is saying pretty unequivocally that one drawing shows a superheated loco and the other doesn't but I still can't see anything on the drawings to indicate superheating or the lack of it.

 

I'm beginning to think that it's just bad phraseology and what he means is, "Here's a drawing/photo of a loco that I happen to know was/wasn't superheated at the time and you have to take my word for it."

 

Edited February 28, 2023 by Harlequin

[The Stationmaster]

According to a former Olad Oak Fui ireman - who I knew quite well in his days as an Inspector you could tell a superheated 94XX from an non-superheated one if you 'went round Greenford' with  a Paddington to Old Oak ECS.  The superheated one didn't use as much water as the other one would have by the time it got to Old Oak 

[Hal Nail]

I'm hoping for help please indirectly related to superheaters.

 

I have a 7mm Finney Bulldog which I bought which may not be strictly accurate but is rather nice so I don't intend to alter it other than potentially number and name.

 

Ignoring the renumbering in 1912, if it is accurate to have a bulldog in this livery and format, I believe it will be in a window of a few years just pre WW1, after fitting a taper boiler and particularly the top feed but before lining was abandoned.

 

So the issue really is the top feed. I have found a website detailing exactly when superheated boilers were fitted to every loco but is that when they got a top feed, or were the two things completely independent?

 

I have found a pic of 3709 which will do but it wasn't named so ideally I'll nail down a better one.

 

Thanks for any help.

 

 

 

Edited April 6, 2023 by Hal Nail

[JimC]

Are you aware aware there are short cone and long cone taper boilers? That looks to be long cone I think (D3 in RCTS parlance) . There are also variations in smokebox length to consider - if I read photos right that's a longer one.  According to RCTS few received top feed *before superheaters* and the first with top feed was March 1911. I fear it's going to be tricky to pin down that exact config without finding a photograph. TBH you could consider leaving be until/unless evidence turns up that it's not right as 3345/Smeaton.

 

 

Edited April 6, 2023 by JimC

[Hal Nail]

10 minutes ago, JimC said:

Are you aware aware there are short cone and long cone taper boilers? That looks to be long cone I think (D3 in RCTS parlance) . There are also variations in smokebox length to consider - if I read photos right that's a longer one.  According to RCTS few received top feed *before superheaters* and the first with top feed was March 1911. I fear it's going to be tricky to pin down that exact config without finding a photograph.

 

Thanks thats helpful. Yes I was aware of different boilers and the source I found lists each so I didn't bother to go into detail here.

 

That 1911 top feed date is interesting though and I agree most of the superheating dates were earlier than that so the two aren't linked.

 

So it's an even smaller window than I'd thought between topfeed fitting and not lining them but having said all that, when I bought it I thought the full lining was completely fictional, so its still far more plausible than it could have been. 

Edited April 6, 2023 by Hal Nail

[Jeremy Cumberland]

For what it's worth, Smeaton didn't have a top feed immediately before the renumbering, since there is a photo of it in The Great Western Railway In The 20th Century by OS Nock, and there is a copy of the page here (for the time being at any rate): https://shop.simonlewis.com/the-great-western-railway-in-the-20th-century-nock-1971-30107-p.asp

 

Don't ask me what boiler type it is. Tapered, obviously, but beyond that they all look the same to me. The tender's different from your picture too.

[Miss Prism]

The combination of lining and a snaphead-riveted smokebox is incongruous. Generally, if lining is still present, then the polished splasher beading was still in place. Splasher beading tended to be removed after the lining disappeared, which is a bit weird, but that's what most of the pics show. I get the impression most Bulldogs lost their lining during the first world war (gradually lost underneath the grime), but few pictures were taken in that period, so we'll never know the actual timeline of the changes.

 

Here's 3434 recently fitted with a top feed and still lined and with polished splasher beadings:

 

 

3345 changed from a full-cone to a half-cone and back again to a full-cone boiler in its life. The strangest thing about the model is the lack of an oval plate. (A few ovalplaters did change to normal arc ones later.) And the wrong cabside shape!

[Hal Nail]

10 hours ago, Miss Prism said:

3345 changed from a full-cone to a half-cone and back again to a full-cone boiler in its life. The strangest thing about the model is the lack of an oval plate. (A few ovalplaters did change to normal arc ones later.) And the wrong cabside shape!

Thanks, that's a cracking photo study and has the cabside handrail which is another variable.

 

This model was restored and had a repaint (before me) so I'm sure it was originally intended to be in later condition, which would explain most of the issues.

Edited April 7, 2023 by Hal Nail

[Hal Nail]

On 06/04/2023 at 21:54, Miss Prism said:

 

Just realised I have this pic in the Maidment book but its in the Dukes chapter and the caption says 1937, so I'd overlooked it!

Edited April 9, 2023 by Hal Nail

[DCB]

On 27/02/2023 at 08:40, Harlequin said:

I've been reading through Russell "... Great Western Engines" Vol. 2 and I've noticed that the text often implies that the presence of a superheater on a loco is obvious from the photos (and to some extent from the drawings).

Not obvious to me! I know what a superheater is and where it is so I'm looking for details around the rear of the smokebox. Sometimes there are a few rivet heads visible but I don't think their presence always correlates with the presence of a superheater.

Sometimes there are helpfully two photos of the same class on the same page, one superheated, the other not, but I still can't see what the difference is!

What are the tell-tale signs of superheating in photos? What am I missing?

 

The problem is you can see which engines and boilers have had Superheaters fitted, as in have been Retro fitted with Superheaters, especially Saints, 28XX, 31XX, 3150 and various 4-4-0s in the 1908 to 1915 ish period even 44XX and 45XX as smokeboxes were lengthened to take the superheater header etc.  However  it's not so easy to see where the Superheaters were subsequently removed or deleted from the design. in 94XX etc. as the taper boiler drumhead smokeboxes were standard stock items and no more short ones were made after superheating was adopted for new boilers.
Superheating works best with locos doing long runs   

Superheating is a big deal, Superheater flues are huge and normally require new tubeplates to be fitted, it's not worth  fitting new tubeplates to a boiler more than a few years old so generally Superheating required a new boiler.  I believe all the high superheat (G) WR boilers were new.  The "Cover" or "larger cover" denotes  the larger three and four row superheaters, on late build BR era boilers.  

Some Dean Goods and Panniers had extended smokeboxes when originally Superheated and later reverted to short(er) smokeboxes much as we know from Airfix and Oxford models.  original ones had much shorter smokeboxes,  First superheated Deans had smokeboxes reaching the front buffer beam, see Russel vol 1.       The GWR Had fully tapered boilers on Manors, Halls etc Castles, Kings etc.   There were no long cone No 2 (Bulldog 51XX 56XX) boilers.  The 2251, 94XX / 15XX std 10 boiler was a short cone with cosmetic long cone cladding. Older no 10s on MSWJR 0-6-0s etc  were visibly short cone.  There was also a No 3 boiler which had the no 10 barrel and the longer No 2 firebox.  It was used on 2-4-2Ts and when the 2-4-2Ts were scrapped some were used on Bulldogs with a distance piece between barrel and smokebox.  Later the same no 3 design was tarted up with a dome after a 40 year gap and fitted to BR std 3 locos