Oil Firing

I'm not sure how the idea of converting a different boiler would be needed or that it would be a permanent or even semi-permanent arrangement came about. Many British engines have been converted for oil fuel going back to the 1920s. Several, including GWR ones, were converted during 1947 when that looked the way ahead. It was quickly found that it wasn't and they were soon converted back to coal firing.

There are modifications needed when going over to oil but they are not structural. They involve some changes to the ashpan, dampers, brick arch and firehole doors, then the addition of firebricks inside the firebox to protect some bits from the fierce flame. The hard part is finding a decent and dependable burner.

 

Unfortunately, as has been mentioned previously, copper boxes are not really suitable for oil firing and both 2873 and 4965's boilers have copper boxes. If Tyseley really are considering converting 4965 to oil then it will be interesting to see how they go about it.
Ray.

 

Indeed. There is a chapter of Holcroft’s book about his experiences with oil firing in 1921 and again 1926. The SECR adopted a system based on Derby practice, and with a kit of parts provided from the main works, conversion was said to take 18 hours and reversion to coal firing only 8. Now obviously that is with the correct components to hand and a running shed full of skilled fitters, but the general point is that the conversions were comparatively simple jobs that could be done by a running shed; not something only attempted at major overhauls.

One interesting practical point he notes of the system adopted was that the burner required a supply of steam to operate. So the equipment had provision for that to be supplied by another loco until pressure had reached about 30psi, after which the oil-fired loco could provide its own steam. Not too much of an issue back in the day, but it would be a bigger issue in a modern context where the oil fired loco may be the only one in steam in a given day.

Tom

 

Think that I remember being told that you can use compressed air to "light up" until there's enough steam pressure to run through the "atomiser"

Both the Festiniog & Rheidol have done coal to oil and back to coal conversions.
I know the former used waste oil - some of it absolute rubbish - for a prolonged period and the latter new oil [diesel ?] - this is going back several decades ! I can still remember the pong some of the Dukesonian mixtures would emit when working hard, and I was at the back of the train and not subjected to the rigours of the footplate in that era. The Alco [Mountaineer] could be regarded as notorious in that area.

 

Did the oil burning Halls and 28xx have steel boxes back in the day?

 

Yes, quite possibly. The context of Holcroft's writing was that the steam was needed to provide atomisation, so presumably compressed air would work as well. He wasn't talking about using it to pre-heat the oil, which is also necessary if you use very viscous oil as your fuel.

Tom

 

I don't claim to be an expert, but I don't think they had steel fireboxes. AKAIK they had standard No.1 boilers.

 

No. Steel boxes were a rarity on Britain anyway and going to oil fuel was made on standard copper boxes. As I've pointed out previously, the copper boxes in the Middle East 8Fs weren't worried by oil firing. I don't know if the GWR ever used steel boxes but I've never heard of it if they did.

 

AFAIK in BR days the VofR used a shore based compressed air supply for 'starting' purposes

 

For some first hand experiences of oil fired steam, admittedly on a ship

https://national-preservation.com/threads/being-a-stoker-on-the-ss-freshspring.1421219/

 

A couple of points about this oil firing lark, if I may be permitted as someone who knows very little about it.

The issue that Tom raises about the need for a steam supply surely refers to the heavy Bunker C type oil used in Holcroft's day before lighter oils became more readily available.

As regards to the issue of copper fireboxes these can indeed be converted for oil firing. However they are unlikely to have as long a service life as a steel box as copper reacts less favourably to the rapid temperature changes involved. This was acceptable post war when boiler overhauls and renewals were an established part of steam operations but best avoided in a preservation context given the high cost of replacing copper boxes. Steel is easier to repair and cheaper to replace, but that said, you can convert a copper box if you so wish.

One interesting issue that arose when locos were converted from coal to oil was the fact that they soon found that superheater elements were getting badly burned at the firebox end because without a brickarch the fire was being drawn part way down the fluetubes. The solution was to reduce the length of the elements.

This at least is my understanding of the situation, but please correct me if you think I'm talking rubbish.

Peter

 

Not quite, he specifically mentions light oils:

The oil used was gas oil or equivalent of low viscosity at normal range of atmospheric temperatures. Although costing more than crudes of high viscosity it was more reliable and obviated the need for heaters on the supply line to reduce viscosity to a suitable degree before reaching the burner.
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My understanding is that gas oil is akin to diesel fuel, and he makes it clear that it was selected so as to avoid the additional complexity of needing to pre-heat the fuel.

The steam jet was clearly for atomisation:

The burner had two narrow slits about 3 in. wide, the lower one being a steam jet. The oil flowing from the upper slit in the form of a ribbon dropped on the steam and was pulverised so that it ignited to flame.
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Tom

 

Stratford ran a considerable number of oil fired loco's around the turn of the 19/20 century, on waste oil from the gas producer plant, which had been discharging into the river lea. The oil burners were designed by Frederick Russell and patented by James Holden. I believe that the oil was viscous and needed steam heating, as well as atomising. The system seems to have been reasonably successful but eventually 'used up' the waste oil leading to a reversion to coal.

 

Thanks for the clarification Tom

Peter

 

Considering disposal at the end of a shift, with a conventional coal fired loco it would be typical to break the fire up but leave it in the firebox to gradually burn down, thus slowing the cooling and contraction process down. Is there an equivalent procedure for an oil fired loco or is there sufficient heat retained in the firebricks?
It wouldn't be a particular issue in "steam days" but much more of a consideration in "preservation".

 

Below is a file which will tell you you the answers to most of the questions on this thread

 

Dick Hardy wrote a piece on this although I've no idea where and when. It took place when he was an apprentice and he was involved with oil firing on, I think, a WD 2-8-0 but don't quote me. He mentions the need to reduce the number of burner nozzles in use gradually during the disposal process specifically to avoid thermal stresses in the firebox.

Wish I could find the article now!

As Tormoraig says and I had also mentioned about the Middle East 8Fs, the superheater elements needed to be shortened to move the return bends away from the flame to avoid their premature failure.

 

Has anyone thought to look at DB (West German) experience given the large numbers of oil-fired locos that were operated or of DR (East Germany) where IIRC bitumen was used as a fuel source ?

 

The Festiniog used compressed air to light up. They eventually gave up on waste oil, partly because of the quality issues mentioned, but also there were regulatory issues.

 

Churchward experimented with steel boxes during the early 1900's, decided not suitable. If I recall, Ahrons comments that many railways tried steel boxes ever since steel became commercially available during the 1860's, but never successfully.