No smoke without coal?

The CPL product has been tried extensively under the watchful eye of the HRA’s coal sub committee. CPL made various changes to their original product and what is available now is good. However, until the price drops below that of coal very few railways are going to buy it on simple economic grounds. The Hargreaves product is similar but has not been subjected to the testing of the CPL one. Hargreaves are also in the coal market, unlike CPL so have little interest in sellout to heritage railways.

 

Think the HR industry will be keeping an eye on the bio fuel costs, and the oil conversions in the US and the North Yorkshire Moors railway.

 

I believe the NYMR have plans for more than 3672 to be oil fired.

 

Interesting that they are trialling it on a loco that won't for 5 years? If they were that concerned why not try it one of the running fleet?

 

As somebody with no knowledge of the specifics myself, guesses I have include:
1 - The NYMR is running a bit short on motive power at the moment (especially large motive power) and doesn't have the capacity to take one of their locos out of service to convert it to oil firing / divert manpower from working on the locos that are closest to being back in traffic to converting an in-service loco to oil firing. And they don't own the smaller locos in traffic so it's not their call as to whether they trial fit the locos with experimental oil firing equipment / they don't want to fit the bill for it
2 - It's a complicated procedure and so they have decided it makes sense to fit it alongside a planned overhaul
3 - They want to apply it to a locomotive which has a larger grate / bit more power in reserve so that if the loco / crew struggle with oil firing there is a greater chance it still has enough power in reserve to work the service. The only locos on the railway with a large grate (about 40sqft) and power class higher than 5 are 3672, 92134 and 34101. They don't want to fit it to 92134, at least at the moment, because of reason 1, and because of the thermic syphons etc in 34101 fitting the oil fired system to it might be more complicated
4 - They want to take time to carefully design the system to give the best possible outcome rather than fitting it soon
5 - The loco needs to be out of traffic for a prolonged period of time to enable measurements to be taken for parts and systems to be manufactured, trial fitted, modified and tested, and they don't want to do that with a current active fleet member because of reason 1
6 - It may make fundraising easier / more attractive for 3672 which many people at the NYMR have a soft spot for but requires a decent amount of money being spent on it before it can run again

 

They don't own the 9F or the Bulleid either, so 3672 is the only option - unless, as you say, they take an operational loco out of traffic for fitment. But as they're so short there's no chance of that happening.

 

The reason for choosing 3672 for oil firing is because it is being overhauled but primarily because drawings already exist for an oil fired WD 2-10-0. Simples.

 

the main reason in my opinion to convert to oil firing is the lack of decent coal now we have to ship it half way around the world rather than use our own supplies I presume the prep time with oil fired is much less so with a declining group of volunteers which a lot of railways are experiencing it makes sense Oil is no less enviromentally friendly than coal

 

I suspect trying to mitigate fire risk also played a significant part in the decision.

 

Fire risk, overnight crew to tend fire not required, maintenance on running gear saving due to no abrasive cinders, oil currently more expensive but the future of the coal supply from nearby Hesperus in doubt.

 

There’s a discussion in Holcroft’s book about a plan the SE&CR had to use smokebox char as a source of fuel to make producer gas. They got as far as doing the analysis and designing the buildings for plant but ultimately the First World War put an end to the scheme.

Amongst the interesting numbers was that the composition of a moisture-free sample was 17.3% ash; 3.4% volatiles and 79.3% fixed carbon. The energy content was 11,205 BTU per lb - not a huge amount less than normal coal.

They reckoned for every 50 tons in, you’d end up with 35 tons of ash at the end, i.e. still have that to dispose of 70% of what you started with. Being a transport company, that was all quantified in terms of wagon loads in / full and empty out, rather than any environmental cost of disposal! But in modern terms, you can’t burn the char away to nothing - you still have some disposal costs.

In the modern world - the question is whether any railway could expect to make sufficient savings to pay for the capital cost of equipment. The SECR scheme was based around making producer gas, not briquettes - but heritage railways don’t need producer gas. I don’t know what the numbers would look like, but it would be a fairly big railway that burns 1000 tons of coal in a year. If you got - say - 50 tons of char, then you get about that amount of low grade fuel, probably worth ~ £10k. Is that worth the capital investment of the machinery to process the char?

How would it work for a railway that uses, say, 100 tons per year and could make, say, 5 tons of briquettes?

Those are fag packet calculations - I don’t know the actual numbers. It would be interesting to investigate, but the machinery to make briquettes has its own costs, both in capital and ongoing maintenance and running costs.

Tom

 

Interesting that 60 or so years later David Wardale was pointing out that the major inefficiency in (coal fired) steam loco's is the unburnt fuel loss and the SECR never asked the question of how do we keep the coal in the firebox and not throw it out of the chimney with all the problems that causes

 

Well, they were interested in electrification which solves some of those problems.

But I think it is easy to get hung up on the inefficiency of steam locomotives, but you need to remember that their primary purpose was to shift an economically viable load. Ideally you want the biggest possible punch in the smallest possible package (within reason - i.e. allowing adequate traction and longevity of the mechanical structure). So efficiency is only one criterion, and arguably even if you could recover all the energy from smokebox char, it might reduce your overall fuel bill by a few percent, and your overall operating costs probably by less than a percent. It probably wasn't worth the effort.

Interestingly they also pursued experiments with a recompression engine, which was designed to avoid the other great thermal loss in steam locos, which is the latent heat of evaporation thrown away when you start with water and exhaust steam. But that didn't work either, I think primarily for the achilles heal of many such schemes, which is the difficulty of arranging an artificial draft to compensate from the loss of conventional draft of exhaust steam up the chimney. Essentially you have to arrange some kind of mechanical fan in the smokebox that can remain reliable while being blasted by a stream of gas and abrasive cinders at several hundred degrees - not easy.

Tom

 

I'm thinking of something a little more cheap & basic as a trial using available discarded containers, available hand tools and PPE, a little cement and volunteer labour as a trial.

 

My experience at Bala when briquettes were first tested is that they did not have the same amount of heat by volume as coal. A round trip uses around a third of a bunker of coal; I was firing twice as much, with a deeper fire that needed topping up much more often. Also, the briquettes would burn through then dissolve into grey powder, which disappeared through the bars. Thus, I could check the fire and it look OK; check again a few minutes later and there would be big spaces, right down to the bars.

They were being tested at Bredgar a few weeks later. Someone tried lighting up a loco in the same way as with coal, a layer across the box - it just sat, no steam, no pressure. He went away for a while and the engineer allowed me to have a go. I filled the box as much as I could and it then steamed. I also had a go on Lady Joan, which wasn't maintaining pressure on the climb. The driver allowed me to fire (it's one-man operation there) and again, he was trying to fire it like coal. Once I filled it to the firebox door it steamed! It still needed regular topping up, though.

The economic case for either would need to take into account the volume burnt for a given amount of work, rather than a simple comparison of cost per ton.

 

In France the AAATV did trials with their 141R 840 to make it run on bio fuel instead of the usual Fioul lourd. The product is called Dertal 600, it's ISCC EU compliant and is produced by a French company called DRT.
While no exact data of their trials were publicised they did release a number of interesting observations:

- After a test at the their site, they decided to test it on a mainline run between Orleans and Tours (75 miles) and back.
- The burner on the 141R was not altered. This was a demand of the AAATV since the loco is a registered monument.
- The oil needed to be heated more than heavy fuel to be able to use it.
- Combustion seemed to be more regular than heavy fuel.
- While the calorific value on paper is slightly lower, this was not noticed by the firemen in active service
- There was no need to clean the smoke tubes during the runs. With heavy fuel this would need to be done 4 times on the same run.

No mention about the price per ton of this type of oil but i reckon it might be interesting for railways looking to convert to oil firing.

 

Funnily enough I am at the moment reading 'Leader and Southern Experimental Steam' by Kevin Robertson. He describes how, in 1929, U boat A629 was converted to burn pulverised coal, without much success though. A crushing plant was erected at Eastbourne and a Terrier used to supply steam to this and the associated hopper. Like the Char mentioned above, a problem was the amount of unburnt and partially consumed fuel, this time deposited on the lineside which led to 'the engine's progress through the Sussex countryside could often be marked by a succession of lineside fires and the ensuing sound of Fire Engines!'
Oh yes and the elevated Hopper burst into flames and covered Eastbourne in a thick black smoke for quite a while and thus the trial was ended.

Chris

 

Can oil-fired steam future-proof rail preservation? | North Yorkshire Moors Railway

 

No, only switching to a non-fossil fuel will do that. The AAATV's trials with Dertal 600 could however, since that's made of tall oil which is a byproduct of wood pulp manufacture. Obviously some form of solid biofuel would be the ideal solution in terms of both futureproofing and authenticity.