6024 King Edward 1

No, very definitely in the context of the erection of the locos at Swindon.

Tom

 

Indeed Steve. The Swindon individual Class drawings lists call the item an Air Pump.

 

But museums are about their subjects. That requires expertise in that subject.

The obituary of Neil Cossons recently demonstrates this - he was a curator who popularised his expert area (Ironbridge, National Maritime Museum, Science Museum) while also focusing on the content.

 

Ignorance of Swindon details and specifications.

 

Because to enginemen its function is to maintain the vacuum train brake. Most references to loco fittings in common use derive from how the footplate crews referred to them. I daresay defects would be booked as eg "vac pump not maintaining".
In displaying such an item in a museum context all facets should be explained.

 

Is there an accompanying technical note to explain the way in which the 'vacuum pump' (sic) works?

 

Indeed!

I agree about the importance of marketing, but I still take the view that sustainable marketing success relies on the integrity of what is being marketed. What Cossons did in the industrial history space, and Roy Strong at the V&A, was grounded in bringing together expertise and marketing, so that they could be both popular and expert.

 

So is it a vacuum pump, or is it an air pump? Is it a railway station or is it a train station? In both situations we all know what people are talking about and as far as I can see both terms are correct in their respective situations.

On the other hand the pedant in me takes exception to the misuse of the term Light Engine.......

Peter

 

Interestingly I looked up the section on brakes in the Black Book. The text refers to a "vacuum pump" and there is a figure caption to a drawing in which the caption is labelled "vacuum pump" (agreeing with the text) but in which the component in the drawing is clearly labelled "air pump"!

I have a hunch that the drawing office and workshop called them air pumps, and the footplate crew called them vacuum pumps, hence the discrepancy. Any subsequent printed sources then vary according to which department they referred for information - so the Black Book, which is primarily a handbook for footplate staff, went with vacuum pump as in common use on the footplate; whereas books like "Cheltenham Flyer" and "The King of Locomotives", which were produced as publicity but were very much in the vain of "look how great the engineering is" got their source material from the workshops and went with air pump. The authors of the Black Book then tripped up because, having described it as a vacuum pump, they went to the drawing office to get a suitable diagram and there it is labelled air pump!



Tom

 

Indeed. You cannot pump vacuum, the air pump pumps air out of the system to create a vacuum.

 

I'm ready to out-pedant the best of them but, as the reason for the pump's existence is to create a (partial) vacuum, I see nothing wrong with calling it a vacuum pump.

 

Well, strictly its both isn't it. Its a mechanisam that pumps air in order to create a vacuum.

But to call it an air pump outside the strictly technical arena would invite confusion with pumps intended to produce compressed air eg Westinghouse.

 

To be further pedantic, the "pump" maintains the vacuum, created by a steam ejector, once on the move ....

 

Wow! My comment has certainly livened up this thread today I did say ‘being pedantic’ and what I said was not wrong. A vacuum is nothing and any engineer will tell you that you can’t pump nothing. You create a vacuum by removing the air in a chamber and, whatever is being used to create that vacuum, it is the air that is being removed to do so.
Whilst in this case I always refer to them as air pumps, I’m the first to admit I refer to the ejector as a vacuum ejector and not an air ejector which I know is wrong, just the same as I refer to a boiler water feed non-return valve as a clack valve.

 

The correct name for the mechanical pump that pumps air to create a vacuum in the brake system on a GWR locomotive is the 'Air Pump'. Officialdom at GWR Swindon nearly always refers to it as such in drawings and documents. Outside of the works at Swindon GWR & BR(W) locomotive dept staff seem to have universally nicknamed it the 'Vacuum Pump', presumably to do so was seen as more appropriate.

The greatest evidence for the Swindon official name of 'Air Pump' is in all the drawing titles which call it such. The GWR Swindon locomotive drawing register, section 15D “brake pumps and cylinders” which runs into 5 pages includes a total of 82 drawings of the vacuum system pumps, and pump parts. Of these 82 drawings all but 3 call it 'Air Pump' in the title, 2 drawings in 1890 call it a 'Vacuum Pump' and one in 1928 which has been subsequently crossed out. The earliest drawing I can find is drawing 6540 of May 1887 “Air pump 5” x 24” for BG (broad gauge) Eng. Lots 74, 75, 79, 81, 82, 83, 85. The last being drawing 134946 of Nov 1955.

I cannot comment on the terminology used in drawing titles for the same device on LMS and Southern region locomotives, it would be interesting to know.

The Swindon locomotive drawing registers are held by the NRM archives ref AA/A/1/25 for sections 1 to 15B and AA/A/1/26 for sections 15C to 28B. These basically list all GWR locomotive drawings associated with a specific part of the locomotive, such as 6E is coupling rods and 8F is horns and ties. Each section being in date/drawing number order. They supplement the full 14 volumes of the registers for all GWR drawings.

Edit. Before anybody raises the subject the device in question does not create an absolute vacuum as some air remains at a pressure below atmospheric pressure, a 'partial vacuum'.

Andy.

 

At work we would always call it at vacuum pump. And that's a chemistry lab!