" Austerity" coal burning

[bricam5]

Something that has puzzled me for years. I have only fired an ex WD austerity twice as a passed cleaner on loan to Springhead but all the blurb I have read about their design and construction say " These locomotives were designed to use inferior quality coal"

Now I would ask. (a) How the hell do you get inferior quality coal to burn? What design tweak makes a bright hot fire out of a load of dross and slack?
(b) If such a design feature were possible, then why were not all loco's subsequent to this,be constructed to burn anything?
I might add that the old H & B lineside used to be littered with Briquets that were mixed in the coal plant at Springhead and were thrown overboard by the firemen.

If anyone can give a reasoned answer to (a) I could sleep easier.

[richard]

Poor quality coal is going to have more sulphur, more minerals (eg. shale), and generally less calorific content per ton. For example, compare Welsh Anthracite (used by the GWR) and the Yorkshire coals used by the GNR and much of the LNER.

Usually this comes down to firebox and grate design (you don't want the mineral stuff clogging up the grate, but you don't want hot coals to drop through - I've never fired a loco, so take this description very generally ). It is usually given as an argument for the wide grates preferred by the GNR and LNER - they are meant to burn Yorkshire coals well, unlike a GWR-style grate.

I would also expect coal/ash/smoke quality also influence the design of boiler tubes, smokebox, self-cleaning smokeboxes,etc.

Quality could also describe the size of the coals?

Richard

[strang steel]

Now I would ask. (a) How the hell do you get inferior quality coal to burn? What design tweak makes a bright hot fire out of a load of dross and slack?

Presumably, extra oxygen provided by increased draughting.

Remember, most UK power stations burn pulverised coal of varying quality. This is 'sprayed' into a furnace through which large quantities of pre-heated air are blown. The coal dust burns almost like oil.

I realise that this is an extreme version, but the hotter that you can get the poor quality coal, the more the solid residue will glow (a bit like coke) and the slack will flare up without killing the fire.

(I have no experience of firing steam engines whatsoever, but this is my conclusion after decades of struggling with open fires and solid fuel Rayburns).

If you were to put high quality coal into this system, it would burn up very quickly and maximum boiler pressure would be reached at the expense of a grate full of ash.

Professional or amateur loco firemen are welcome to pull my theories to pieces.

[Blink Bonny]

Ay up!

The only addition I can make to this - your comments seem thoroughly reasonable to me, gentlemen - is that the ashpan capacity would need to be greater to burn dross than decent stuff, due to the higher ash content.

[Boris]

Never had an Austerity that wouldn't steam whatever s==t you had in the tender.
If they started to get a bit shy then the secret was to open them out a bit.

I used to own the only 7.1/4 gauge Austerity in the U.K and she was the same
Going up the steep bank at the Waltham track near Cleethorpes with 16 passengers on 4 trucks she would blow off nearing the top with one of the injectors on.

Broke my heart to sell her but got to old and decrepit to work her any longer.

[manna]

G'Day Gents

Wasn't that one of the reasons that GN Atlantic's had the wide firebox, so that they could burn poorer coal (could be well wrong here )

Boris, have you a picture of your Austerity

manna