Steam Locomotives and Oil Firing

Getting back to oil fired steam locomotives, how about this for a teaser; what would be the consumption of a locomotive using oil rather than coal?
I note that in action a 'Clan' was checked as having used 31.4lbs/mile on a trip whilst a 'West Country' used 50lbs/mile.
Anyone like to hazard a guess, or even better a calculated opinion, on what oil firing would achieve?

Many years ago I worked on 'fluidised combustion' which was expected to enable boiler plants to use the thick oil tar which was waste otherwise. Excellent system, timing was all wrong so did not succeed. Sounds similar to the GPCS system perhaps?

 

There are some figures given in Holcroft. Unfortunately, there aren't any directly comparable engines (mostly they experimented with smaller engines), but some typical figures are as below. The SR system was a hybrid coal / oil system, with the main combustion being oil, but a small coal fire maintained in the firebox. Careful measurement of consumption indicated that, in energy terms, the coal was providing about 20 - 30% of the energy and the oil about 80 - 70%, depending on the engine. The oil was "gas oil" with a low viscosity, that didn't need steam heating in order to flow.

The closest to a modern loading and existing engine I can find:

N15 (King Arthur class) No E739 Waterloo - Salisbury and back, load 13 bogies / about 350 tons down; 11 coaches / 311 tons return. Stops at Surbiton, Woking, Basingstoke and Andover. Combined consumption was 18 lb oil / 11 lb coal per mile.

Tom

 

Thanks Tom, a good comparison for loadings even if the motive power is slightly lower than the 2 examples I quoted.
If we worked on 20lbs of oil/mile as sole fuel, which may or may not be achievable, to replace the 7 tons of coal carried by the original Clans, for example as I have figures to hand, (giving approx 450 miles range), an oil capacity of 4 tons is required, which appears to convert to about 65 gallons. [Are my sums correct?]
It would appear that there would be sufficient spare room for additional coal to keep the fire going, as in the N15 example.

An interesting thought perhaps.

 

I think the figure of four tons may be correct, but 65 gallons is a bit low (my Astra holds about 12 gallons).

At 20 lbs per mile you would need 9,000 lbs of fuel. If we were talking about water, a gallon weighs 10 lbs, so the total would be 900 gallons. But since oil is lighter (less dense) than water, the volume required would be a fair bit higher than this, certainly well over 1,000 gallons and maybe nearer 1,100 gallons. Anybody know the specific gravity of "gas oil"? Or the volume of the coal space in a Clan tender expressed in gallons?

 

An article in The Locomotive for March 1947 has a drawing of the oil tank in a small GW tender and quotes a capacity of 1,800 gallons of oil (Bunker C).

 

Let's look at this a bit more accurately. Coal is typically around 30 GJ/Tonne net, and Gas Oil around 40GJ/Tonne net. So if you replaced the coal by oil on the N15 you'd need an additional 11*30/40 = 8.25 lb/mile of oil, giving a total of 26.25 1b/mile. Equiv to 11.9 oil kg/mile. So for 450 miles you would need 5360 kg. Density is 835 kg/m3 , so that equates to 6.42 m3, equivalent to 1412 UK gallons.

I have never heard of co-combusting oil and coal in a firebox, so I've learnt something there - sounds a very messy arrangement though! I'm sure there are figures out there for straight oil firing?

 

Well done for putting up with that earlier sh*t mick, but i must correct you yet again, the currently accepted term is Sex -Workers. ...

 

I'm a fireman on 745 a US gauge 2-8-2 Mikdo we use about 10gals of oil a mile when running about 45 MPH and 100gals of water.

 

I don't think you can get the very heavy fuel oils any more - they just aren't available in most UK ports

 

That's US gals right?

 

Takes me back to the days of my youth and the joy of joys that was a cold start on an oil fired steamship...................

That and the heady smell of sulphur.

 

Given the way the thread has gone, was using the expression 'the game' the most appropriate of terms to use?

 

Ah memories as a J/E of 12 hours of 15mins on 15 mins off on Diesel warming through then another 12 hours plus getting up to 60 bar with the roar from the superheater circ vent as full pressure was reached.
Some of our motor ships also had big three furnace fire tube scotch auxiliary boilers which had 30 tons of water in them, these were also gently warmed through and never rushed into service.

When I had climbed the greasy promotion pole I was asked to trial refinery Atomospheric Residue as a fuel in some header boilers. What a disaster, wore the IMO screw boiler fuel pumps out in about a month in spite of treating the fuel with polishing filters. Burner Fuel tips wore out in a similar time and because the components of the fuel burnt at different rates in the furnace we found it impossible to prevent massive carbon formations building up on tubes and furnace walls. Experiment cancelled never to appear again thank God.

On Motor ships using HFO the bright yellow Sulphur built up around the exhaust valves and really stung if you got it on your skin. Some fuels left a yellow flue gas trail in the sky from the funnel right back to the horizon.

I was under the impression railway locos never used this really heavy thick stuff, certainly the big German Pacific I had a look at the other year in steam was on Gas Oil. Even so the Gas Oil leaves carbon/soot after a time in the fire tubes which was/is removed by injecting sand or using a steam lance through the burner aperture.

Brian

 

The Great Eastern Railway used oil firing extensively at the end of the 19th century. The reason was that the GER's gas works at Stratford was producing a thick oily by-product which was being discharged into the neighbouring Channelsea River. The Railway was threatened with prosecution by the local authority and "something had to be done", so using the oil as loco fuel killed two birds with one stone, or at least, saved a few birds on the river!
I'm not sure of the technical details of the equipment used, but oil-firing was used for a number of years and on "top-link" services, so it must have been fairly successful.

Oil firing has been and is, widely and successfully used overseas. The Canadian Pacific, like many North American railways, used oil to fire steam locos in the '40s and 50s and 2816 "Empress" burned oil in her recent and now, sadly curtailed, mainline career. She certainly seemed to be running very well on oil (gas oil/diesel I believe) and I was told that it was cheaper to run and easier to maintain, in spite of running through a major coal producing area, most of which CP carries.

 

The German oil fired locos certainly seemed to do the job and youtube videos of the North Amercian Railway oil fired locos are very impressive.
Have only seen simple Gas oil distillates or only slightly higher viscosity oils used as fuels needing low heat hence my question re HFO. HFO to me means fuel with an SG of almost 1 and which has to be about 160F + for it to be pumped, the pipework needing to have tracing heating or because if let go cold it cannot be pumped or burnt easily. Were the burners always simple pressure jet and was steam atomizing ever used?

Brian

 

ISTR that I have seen references to the Midland design 2Ps that were converted to oil burning during the General Strike keeping their fuel oil in the tender mounted tanks hot via steam from the locomotive, and that it had to be kept hot whilst in storage. This would suggest that it was a thicker grade than gas oil.

 

Yes CP 2816 used diesel as it was cheap to get , although it does tend to slosh about a bit -- we used it on 2860 but found on harder stops the fire went out ...we have since gone to recycled oil ...when we run . As for the coal in that area of Canada , tends to be better for industrial use than steam loco s ...and don t forget the forest fire danger ..sparks not welcome ..lol

 

I think in the UK all oil firing applications required the oil to be heated to reduce its viscosity, and was probably close to being crude oil. It isn't an area in which I've dallied, though!

 

In "Locomotive Adventure" by HA Holcroft, he states (about the SE&CR trial of oil firing):

"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 necessity for heaters on the supply line to reduce viscosity to a suitable degree before reaching the burner."

He also notes that the system used was based on that developed by the Midland Railway, rather than the GER system. The system used mainly oil, but maintained a small coal fire both for ignition purposes and to avoid large temperature fluctuations in the firebox when the oil supply was shut off.

Reading between the lines of the account he gives, I think simplicity of installation in coal-burning boxes was prioritised over fuel cost. I think what the SE&CR (and the SR after them) wanted to develop was knowledge about a system that they could implement very quickly and at minimal cost in the event of a coal shortage (such as during a strike) rather than developing a system for the inherent cost or other advantages of using oil itself. I can't find the reference now, but I seem to recall that the engines they trialled only needed a day or so in the works to fit the equipment, and even less to remove it.

Tom

 

Actually its the other way round. Most virgin crudes flow quite freely at normal temperatures as they still contain all the high value distilates. After after the naturally evaporating gases are taken off, simply described the crude is heated and as the grades of petrol, paraffin, gas oils are boiled off at increasing temperatures and condensed into fuels, the residual oil gets thicker and thicker until after HFO you are left with tars and the stuff I had to trial burn - atmospheric residue which also contained all the nasty 'heavy metal' pollutants.
The only use of neat crude oil as a fuel I know off was certain shipping companies operating VLCCs diverting some of their cargo into the bunker tanks as 'free bunkers' Not really a good idea as the crude mix then exploded in boiler furnaces, pumps etc and caused loss of ships engineers lives and even some ships as I recall it.
If you did not purge the furances properly or tried to 'flash' your fuel off hot carbon when relighting the burners without going through the purge and relight sequence it was possible to achieve quite a bang and I have seen reports of furnaces that were physically reshaped as a result. I think I have read one or two locomotive suffered from this as well. Coal is much 'safer' as an inert fuel in handling and firing although if you heap enough of it together spontaneous combustion becomes an issue.

Brian