Steam loco pipes identification

[The Nth Degree]

I'm trying to identify various pipes and equipment on a picture so I understand what a book I'm reading is talking about. I know some basics, but the small stuff is very difficult – one pipe looking much like another. Here's the labelled picture:

I don't think the actual prototype is important, but if it is this is a J67. My questions, please:

A: What is under this dome? What does it do?

B: What is this for?

C: Ditto

D: Ditto

E: Ditto

F: Ditto

 

I know this has Westinghouse brakes, but does it also have steam brakes? How would one tell if it did? What is a steam ejector and what does it do? These questions may be answered from the questions above.

 

Thanks very much in advance.

[Spitfire2865]

Well the dome is probably the steam dome, which is where the steam rises to, and is forced through the openable valve controlled by the regulator.

B looks like a blower for helping steaming, though that may be wrong.

D looks about the right location for the ejector, but Im probably wrong there. Dont know the J67s.

And the loco does matter as different locos would have different pipes in different places. Understanding the design is important to knowing its function.

 

An ejector is for vacuum brakes AFAIK.

[JeremyC]

A - steam dome. This is the point steam is drawn from. As it's the highest point in the boiler it reduces the chance of water being carried over as well. The regulator valve is often fitted in here. What you see is just a cover the real dome is underneath.

 

B - Ejector pipe (I think) for the vacuum brake ejector. The ejector is the equipment that creates the vacuum. Note this loco is also fitted with a Westinghouse air brake pump.(On the tank front).

 

D - Clack valve. A non return valve in the boiler feed water pipe. The name is said to come from the noise it makes.

 

E - On looking at some better photos of J67/69s this pipe seems to be connected to the Westinghouse pump.

 

F - Possibly the operating rod for the sandbox

 

Jeremy

[Sweedy]

B - as identified previously, this is the vacuum brake ejector pipe

 

C - Blower valve lever; a later version which replaced a Worsdell type blower valve. The operating rod passed through a hollow handrail on the right hand side.

 

E - This valve only appears on the Westinghouse brake fitted engines and is part of the plumbing for that system.

 

F - Confirmed as the actuating lever for the front sandboxes. A similar rod featured on the left hand side.

 

My understanding is that Westinghouse fitted locos did not have a separate steam brake. Where Westinghouse and Vacuum systems were fitted, the Westinghouse provided the locomotive brake, the vacuum system the train brake. Where the Westinghouse brake was not present and vacuum brake was, the locomotive brake was a steam brake, again with vacuum operating the train brake. In both cases where more than one system was present, there was a combined operation system to allow the actuation valves for both systems to work in conjunction.

[The Nth Degree]

Thanks very much gents, that helps enormously. I can follow what's written much better now, and comparing photographs now makes sense.

[IWCR]

E   would  be  the  Westinghouse  exhaust  pipe.

This  takes  the  used  steam  from  the  pump.  enters  the  smokebox and  is  then  directed  upwards  into  the  chimney. 

The  end  would  be  at  the  level  or  slightly  above  the  blastpipe  top.

 

Pete

[The Nth Degree]

One more question, if I may. What identifies this loco as having steam brakes? I can see a pipe running along just under the running plate – is it that?

 

As before, thanks very much.

[LMS2968]

Nothing on there would show the type of brake used on the engine, and in theory you have a choice of steam, vacuum and straight air. Everything visible concerns the trains' braking, the loco was a different issue.

[The Nth Degree]

Ah, great – that makes life a LOT easier.

 

Final question, and this probably can only be answered by some very specific GER/LNER experts: the loco pictured is a GER S56, which is mechanically very similar to the GER R24 and C72. Many of these locos had a flush-riveted smokebox shroud, but some had these riveted types (as pictured). My question is, what would determine which type of smokebox shroud was fitted? Are they particular to a certain type of boiler – Diag 37 or 39? Or was it a war-time replacement for speed or economics? Maybe it was whatever they had in stock or could reuse from the older J tanks? I'm really confused by this, so anyone with clarification would earn themselves my eternal gratitude.

 

Steve

[Sweedy]

As noted above, the pipe you can see relates to the train brake not the loco brake, i.e. not the steam brake. Specifically it relates to the vacuum brake, not a Westinghouse installation.

 

As for use of snap head rivets, I have looked through notes that I have in various books. A note in the instructions from the Alan Gibson J15 kit suggests the LNER started using them from circa 1935. A review of photographs (e.g. in RCTS Vol 8A and Yeadon's Vol 48) suggests no relationship to a particular boiler or type of smoke box. The loco you have shown in the photo is 7082 circa 1944. I suspect use of the snap head rivets depended on the type of work undertaken and whether the smokebox wrapper had to be removed. It may also depend on the workshop that undertook the work. For this reason when modelling these locos you need a dated photograph to see how these and other details apply.

[The Nth Degree]

Great, thanks Sweedy. That's one very unpredictable cat among the pigeons.

[The Nth Degree]

Just when I thought I'd finished my questions I find I have another couple, this time concerning blast pipes and blower valves.

 

Firstly, what did they do? Were they fitted from new? Were they removed later? I've found several pictures of these engines, some with, some without, and those with have several designs.

 

It seems that blast pipes were on the left-hand side, when looking down the loco, and blower valves on the right. Blast pipes seem to be variable and blower valves either have an elbow pipe into the smokebox or a crank.

 

From what started as something simple has turned out to be very complex.

[LMS2968]

The blastpipe is entirely contained within the smokebox below and immediately in line with the chimney, but with an air gap between. It was open at the top, but to a very specific diameter and shape. It sent the steam exhausted from the cylinders up through the chimney, taking the air in the smokebox with it. This created a vacuum in the smokebox, the effect being to draw air through the tubes, ash pan and fire. It thus created an artificial blast on the fire, causing it to burn far hotter to generate more heat and therefore steam in the boiler.

 

This worked only when the loco was running with steam on. Standing or running with steam off produced no blast so the fire would die down. The blower used steam from the boiler directed upwards from a series of holes around the blastpipe's periphery through the chimney, with the same though lesser effect as above.The valve controlling this was often in the cab, but could be on the side of the smokebox and opperated by a control rod from the cab.

 

Neither would be removed during the loco's working life.

[Sweedy]

The GER buckjumpers (and other GER locos) were fitted with a variable Macallen type blastpipe. One of the first things that happened after grouping was removal of the variable blastpipe and its operating mechanism with replacement with a plain blastpipe. What you can see on the left hand side of the smoke box towards the front is the operating lever and crank to change the setting for the variable blastpipe. (Note on locomotives fitted with condensing gear, the operating lever for this was also on the LH of the smokebox side close to the flange ring at the junction with the boiler itself).

 

So far as the blower operation is concerned, the earlier engines used a Worsdell type. This had a blower valve on the top right hand side of the smokebox operated by a rod from the cab (the blower itself is a ring around the blast pipe within the smokebox as described by LMS2968 in post #13 above). Later batches of the locomotives had a different activation system using a crank on the smoke box side at the level of the handrail with the operating rod passing through a hollow handrail. Where this type is fitted (e.g. in the photo of 7082 in this post) you can see two handrail stanchions on the smokebox either side of the crank.

[The Nth Degree]

Thanks both, really appreciate it.

[kenw]

It seems that blast pipes were on the left-hand side, when looking down the loco, and blower valves on the right

Where vacuum braking was fitted, the ejector pipe would be on the driver's side

[kenw]

One more question, if I may. What identifies this loco as having steam brakes? I can see a pipe running along just under the running plate – is it that?

The type of brake fitted to the loco wouldn't normally be visible, the equipment being between the frames. Several NER 4-4-0 classes though did have a visible westinghouse brake cylinder at the bottom of the frames between the driving wheels.

 

The combination of loco / train braking varied depending on company, or individual CME practice and preference. On an LNER theme, most of Gresley's locos including the pacifics had vacuum for both loco and train braking, the Thompson and Peppercorn locos had steam brakes with vacuum providing train braking only.

Where Westinghouse train braking was fitted, this generally seems to also provide the loco braking. Hence several ex-NER classes are seen retaining Westinghouse equipment long after vacuum train braking had been standardised.

 

Where dual systems were fitted, there'd be a proportional valve or similar arrangement on the train brake to control the loco brake, and with dual train braking, the driver's brake valve normally would operate the Westinghouse brake, which in turn controlled the vacuum if in use.