How far does your loco run on its coal and water capacity?

[MR Chuffer]

Perhaps the all day-shunting was anecdotal, after they'd been built; sure I saw it somewhere, and sure it was MR, but perhaps not...

[Siberian Snooper]

As there's a MR half cab preserved,  it should be relatively easy to get some sort of idea of its consumption of coal and water. I would suggest contacting Barrow Hill,  but a response may have to wait until we're allowed out to play again.

 

 

[Steamport Southport]

It would be the same as any small shunter.

 

Fill it up with coal and water at the start of the day and top up with water as needed. The coal would last until it finished work, if not days. However water boils constantly whether it's being used or not. There would be a water tank or crane within easy travelling distance.

 

Get a diesel, they lasted weeks on one tank. 

 

 

 

Jason

[The Johnster]

Locos were by and large designed with enough coal bunker capacity to manage their days work, or had coaling booked into the duty, on the basis that water could be obtained everywhere.  Water couldn't be obtained everywhere and this figured in drivers' assessments of when they needed to take water, as they had to do it a) where it was available and b) without causing delay to other traffic.  Causing delay to other traffic has the potential to upset other drivers' assessments and increase the likelihood that their need for water in unbooked or unexpected places would further disrupt traffic.

 

All part of the fun of driving a steam loco.  The driver is responsible for ensuring there is enough water in the tank, and the fireman's first responsibility is to ensure that the water level in the boiler is sufficient at all times; running out of water is a much worse offence than running out of steam, and almost as bad as letting it get into the cylinders...

 

Target Auto JB at Abercynon shed; 64xx LE Pontypridd attach 2x auto trailers, work to Cardiff Clarence Road via Barry Rly and SWML (St Fagan's), 2x return trips Clarence Road-Penarth, then Clarence Road-Pontypridd, crew relief, then repeat for afternoon shift, a respectable mileage for a main line turn not a local auto duty, and involving a good bit of collar work on the banks, all on one bunker of coal with a loco the size of most used for general shunting duties on main line railways.  BTW, there was no water available at Clarence Road, or time to take it at Cardiff General.

 

Shunting duties on large sites such as the GW owned South Wales docks could take a loco a long way from the nearest available water as well, so their drivers had to keep an eye on the situation, and a ship missing a tide because the loading was interrupted was a serious matter.  Coal was never a bother.

[Lecorbusier]

4 hours ago, Siberian Snooper said:

As there's a MR half cab preserved,  it should be relatively easy to get some sort of idea of its consumption of coal and water. I would suggest contacting Barrow Hill,  but a response may have to wait until we're allowed out to play again.

 

 

Already done that to no avail ... hasn't been in steam for a fair while so no one with a working knowledge. I did ask about the 4f on the West Sommerset mid 2018 and got this response.....

Quote

Sorry the Locomotive is out of traffic at the moment and unlikely to return to until next year,
 
It seems to be better than the books would tell you, average use of 750 Gallons to do the 20 mile one way trip. ( out of a 3000 Gal Tender) ...Based on 6 carriages at 37 tons

 

[Siberian Snooper]

From that, I would deduce that your 1f will do around 20 miles or so with about 150 tons hanging on the hook. I have not done the full length of the WSR, but I believe it's a bit of a rollercoaster route

 

 

[johnofwessex]

Its worth pointing out that crews were sometimes instructed not to use certain supplies unless strictly necessary because of the payment arrangements, for example while there is a water tower at Minehead it was fed from the town supply which had to be paid for while the supply at Williton came from the river by the station so was free.  I understand that in 1922 instructions were issued to S&D crews about not using the supply at Wimbourne if possible for this reason.

 

I believe that some supplies also had quality/reliability issues which - for example why the VofR now normally waters at Nantyronen not Abberfrwd

Edited May 16, 2020 by johnofwessex
corrected

[TheSignalEngineer]

On 15/05/2020 at 10:36, Compound2632 said:

I've been quickly scanning through photos of Birmingham Central Goods and Lawley Street on Warwickshire Railways - haven't spotted any water columns. Both are seen being shunted by single-cab 0-6-0Ts - 1377 Class - c. 1922. 

I can't remember water columns at either. Lawley Street originally had a shed and was directly opposite Saltley shed so no problem there. The nearest I can remember to Central Goods was at the back of Five Ways station a few hundred yards up the branch towards the main line.

[RobinofLoxley]

AS this thread has become a current topic in another I thought I would add something.

 

Having a long term background in steam generation amongst other things I would just point out that statistics for coal consumption would be pretty meaningless if they didnt address seasonality. The firebox is basically going to heat the entire engine over time and in the case of passenger stock, those too. Summer water from towers standing in the sun could be up to 30C where it would be just 3-4 in winter. All this would add up to a 30% differential in fuel usage winter to summer. Boilers require a large percentage of their fuel just to get to operational readiness.

[Compound2632]

2 hours ago, RobinofLoxley said:

AS this thread has become a current topic in another I thought I would add something.

 

Having a long term background in steam generation amongst other things I would just point out that statistics for coal consumption would be pretty meaningless if they didnt address seasonality. The firebox is basically going to heat the entire engine over time and in the case of passenger stock, those too. Summer water from towers standing in the sun could be up to 30C where it would be just 3-4 in winter. All this would add up to a 30% differential in fuel usage winter to summer. Boilers require a large percentage of their fuel just to get to operational readiness.

 

For a 19th century locomotive flapping along on saturated steam at around 150 psi (10.3 bar) the boiling point is 185 °C, so the difference is less than might at first appear - 14% less with water at 30 °C than at 5 °C.

 

For such a locomotive, with a tender of 3,275 gal capacity and a boiler holding around 725 gal, the total mass of water to be heated and converted to steam is around 18,000 kg. Specific heat capacity of water C = 4,200 J/(kg °C ) and latent heat of vaporisation L = 650 J/kg, so the total energy required to boil all that water is about 13 GJ. The energy released on combustion of hard black coal is around 25 MJ/kg so if the locomotive was perfectly efficient only 520 kg of coal would be needed - about half a ton. A typical 2-hour trip might in fact use all the water but only half a tender-full of coal - about 2 tons for my 19th century 4-4-0, assumed to carry enough coal for a round trip - implying roughly 75% of the heat from the coal goes to waste.

 

Back-of-an-envelope stuff - is it reasonable?

[RobinofLoxley]

7 hours ago, Compound2632 said:

 

For a 19th century locomotive flapping along on saturated steam at around 150 psi (10.3 bar) the boiling point is 185 °C, so the difference is less than might at first appear - 14% less with water at 30 °C than at 5 °C.

 

For such a locomotive, with a tender of 3,275 gal capacity and a boiler holding around 725 gal, the total mass of water to be heated and converted to steam is around 18,000 kg. Specific heat capacity of water C = 4,200 J/(kg °C ) and latent heat of vaporisation L = 650 J/kg, so the total energy required to boil all that water is about 13 GJ. The energy released on combustion of hard black coal is around 25 MJ/kg so if the locomotive was perfectly efficient only 520 kg of coal would be needed - about half a ton. A typical 2-hour trip might in fact use all the water but only half a tender-full of coal - about 2 tons for my 19th century 4-4-0, assumed to carry enough coal for a round trip - implying roughly 75% of the heat from the coal goes to waste.

 

Back-of-an-envelope stuff - is it reasonable?

Some dodgy numbers in there but the conclusion is highly plausible. Conventional coil boilers never extracted much more than half the available energy so factoring in everything else 25% could be right

[Compound2632]

1 hour ago, RobinofLoxley said:

Some dodgy numbers in there but the conclusion is highly plausible. Conventional coil boilers never extracted much more than half the available energy so factoring in everything else 25% could be right

 

Interesting. As I said, back-of-the-envelope. Which numbers would you question?

[RobinofLoxley]

16 minutes ago, Compound2632 said:

 

Interesting. As I said, back-of-the-envelope. Which numbers would you question?

I havn't checked the numbers properly but the latent heat value of water far exceeds the specific heat value. Otherwise there would be no point in generating steam. Maybe you have slipped a decimal point somewhere. Having retired I have binned all my source material...

[Compound2632]

4 minutes ago, RobinofLoxley said:

I havn't checked the numbers properly but the latent heat value of water far exceeds the specific heat value. Otherwise there would be no point in generating steam. Maybe you have slipped a decimal point somewhere. Having retired I have binned all my source material...

 

The value I've looked up just now for the latent heat of vaporisation of water at STP is 2,260 kJ/kg so I think you are right, I've bludered somewhere. It's also possible I've misinterpreted the graph I was looking at for its dependence on pressure.

Edited February 11, 2021 by Compound2632

[Dagworth]

According to Google 

 

“The heat of vaporization of water is about 2,260 kJ/kg”

[Compound2632]

1 minute ago, Dagworth said:

According to Google 

 

“The heat of vaporization of water is about 2,260 kJ/kg”

 

At STP. But were at somewhere around 10 bar.

[Dagworth]

Ah yes of course! Physics at school was a long time ago! 
 

Andi

[RobinofLoxley]

That is why you need a steam table to find the total energy value of the steam. The energy holding value of the steam increases as its temperature and pressure rise together, so at 10 bars that you mention the energy in the steam is something like 2650kJ/kg and its corresponding temperature about 170C

[RobinofLoxley]

Its a fun fact that on my 65th birthday Mrs ROL took me to York to the NRM. At a certain time there was supposed to be a talk at one of the locos on how they worked, that is how the boiler used to produce motive power. The normal individual didnt show, so I volunteered to give the talk impromptu. It was quite successful.