Firing models

[arch1947]

Hi Everyone, I have just fired up my Bridget again and find I am getting better at it and gradually clearing up the annoying little problems. My question is: Are there any books on how to fire a model steam locomotive. I know the techniques vary from model to model but I thought there may be a general text around.
Cheers,
Arch

[Deleted]

Judging by the name this might be what you're looking for >>>>>>>>>>>>> "How to drive a Steam Locomotive" by Brian Hollingsworth....ISBN 0 14 00 5529 0 ------- This on E-Bay >>>>>>>>>> www.ebay.co.uk/itm/How-to-Drive-a-Steam-Locomotive-By-J-B-Hollingsworth-0906525039- ----------/3107668032

[wiltsrob]

Arch

There isn't any particular text around for models that I am aware of, the book suggested is a great book and very insightful. from experience of driving my rail motor I would suggest a fairly thin fire with as the other thread suggested little and often.

The other thing I have noticed is people will insist in using the biggest lumps of coal they can fit through the fire hole door.... my 7.25" A4 runs far better on the small bean that the club uses for the 3.5/5" gauge loco's than it does on the large lumps more suited to narrow gauge engines. the only thing I have to do is provide a bit of secondary air as the fire burns a bit hotter and a bit faster.

All I can suggest really is every time you steam up try something a little different and when you fine something that works for your engine stick with it.. if you get chances to drive other peoples engines ask how their loco likes to be fired/driven... whenever I let someone drive my engines I always tell them how to best fire the engine no mater how experienced a driver they are, as you say each engine will have its own quirks and personality.

Robert

[arch1947]

Thanks Robert, Each time I fire up Bridget, if you will pardon the expression, I learn something as you say. I am keen to get onto the track but need to have a better understanding how things change. I will check out the eBay book too. My main concern is maintaining water level but I am happy now that the injector is working and the axle pump certainly loads up the loco when the bypass is fully closed. It all looks pretty simple until you have to do it. Thanks for you advice and please keep it coming. I am happy building these things but driving them requires a different set of skills.
Cheers,
Arch

[steam4ian]

G'day Arch.

There is going to loads of good advice but it will only be as good as it is tuned to the coal you are using and the track you are working.

Coals with a lot of volatiles will catch easily and shallow fire beds fired often are OK, too thick a bed with these coals will run you short of secondary air. At SASMEE we burn Char with not much volatile and a thicker fire bed works OK. I generally fire at only the station which works because we have a long grade away from the station and just a little bit of blower is enough to get the fire going by the time you have to haul up the long grades. Other fire on the short flat interval in the long grade both approaches work the latter probably a bit better because I tend to be blowing off by the end of the grade unless I open the fire door. Firing this way has the same results over a number of locos I have driven. BTW one lap of SASMEE takes about 3 minutes.

Some differences between full size and miniature are:
Every thing happens quicker on the small sizes.
You, the fireman, are also driving so the fire is only one thing you are concentrating on.
It is more difficult to aim a scoop at a rocking fire hole than a shovel in full size practice.
A scoop of coal will cover a large portion of the fire bed compared with full size so two scoops can often deaden the fire in a narrow firebox.
Opening the fire door has more effect on the fire and less risk to the tube plate (unless expanded in tubes) than in full size.
This all diminishes the relevancy of some full size practice.

Arch, I don't believe there is a wrong and right way, just what works for you.

Ian

[GeorgeRay]

Arch
The most important thing with a Bridget is to make sure you have a firing shovel that enables you to reach all of the grate. I spent a frustrating hour try to carry out a steam test with the fire only covering the back half of the grate. Once the shovel was modified to reach the front of the grate steam pressure actually appeared. once you have steam then little and often is the rule. Making sure you are covering the grate. As Ian says it is difficult to you throw fuel where you want it you need the shovel to put it where it needs to go.
George Ray

[marshall5]

Arch,
I wrote a pamphlet for new steam drivers in the Manx Steam and Model Engineering Club. Whilst it is directed towards our track 'The Orchid Line' some of the general hints and tips may be useful. I can e-mail you a copy if you like and you can print it off yourself. Ray.

[arch1947]

Thank you all very much for the sage advise. Once I get a couple of the annoying leaks fixed I intend to go to the track during the week and have a go at driving Bridget "for real" and try some of what you have said. George, my shovel does have a long handle so I can reach deep into the firebox, not sure how I will go sitting on the riding car though. Ray I would be interested in the pamphlet, every little bit helps.
Cheers,
Arch

[steam4ian]

G'day Arch

I forgot to ask what coal you are using. Is it from Fingal Valley or something you have imported from the mainland? The first time I ever saw coal burning in a grate was in the cottage of a retired miner at St Marys; he still got his free supply even though that pit had closed.

BTW, make sure you shovel has a rounded back so it doesn't catch on the way out for the firebox. On one loco I fire with a long fire box I turn the shovel over and push the fire forward before I add more coal at the back. With char which is low in volatiles you can keep the fire up to the fire hole with no ill effects. In fact our efficiency trial works do just that; you fill the fire box to the fire hole at the beginning of the run and again at the end and measure the weight of the total coal consumed including that fired along the run.

[arch1947]

Hi Ian, We use char at ELRSS and Briquettes as well but I have been concentrating on char. As you probably know char is likely to be hard to get in smaller quantities soon so I will try both. I like the idea of having the fire right up to the fire hole, it means one less thing to worry about when running and this is the practise with our large 7 1/4 club loco. With luck I will get another shot at it this week before going to Melbourne for Christmas.
Cheers
Arch
PS Will you be attending the AALS convention is 2014

[wiltsrob]

Arch

before you next fire the engine have a look into your fire hole door... it is fairly common practise these days ( especially on the commercial boilers ) to put the fire hole door as close to the top of the inner wrapper .. you might find having that deep a fire is blocking your lower row of tube which will noticeably reduce your steaming capacity

[jma1009]

BRIDGET has quite a deep level (non-sloping) firebox. different types of firebox require different firing techniques.

generally i wouldnt pile the coal in at the back of the firebox up to the bottom of the firehole door on a firebox such as BRIDGET's. a level and even depth of fire should be aimed at. it is better to have a thinner fire firing little and often then pile on loads of coal all in one go.

firing with a deep fire at the back of the firebox is the sort of thing you would do on a GWR boiler with narrow firebox and sloping grate. i think that such fireboxes are more difficult to fire.

i dont have any experience of burning the coal you have 'down under', so completely different techniques may be required.

good luck with the steam up at the track next week! do let us know how you get on.

cheers,
julian

[Shawki Shlemon]

Hi Arch , as far as I know that clubs in OZ are required to train the new members and issue a competency certificate to drive the locos on club grounds , I am sure that the person/s doing the training must have experience in this area and you should get some help from him/ them .The char / coal is a problem these days , we are trying a few sources and have not selected a choice yet , this is because we lost the source of regular char provider in Victoria .There are many variables , the coal , the size of beads , the design of grate , the depth of the fire box , the size and number of fire tubes and the airflow to mention a few , try different things and ask for advice from others and I am sure that eventually you will find the best method for your engine .

[steam4ian]

I hear what Julian says but a thick fire of the char we burn in Oz seems to work. no body in our club has queried a thick fire

The matter of Char supplies comes up at every club meeting. At the last meeting a bloke from Clare Valley LS said they are getting some from a place in Bacchus Marsh. I knew there was a pit there but didn't know it was still operating let alone making char.

The problem is not one of it being manufactured rather volumes they are prepared to sell. It used to be obtainable in 1 cum Bulky Bags now the regular supplier will not deliver in any thing less than a semi load.

Arch we supply broken up briquettes for lighting up, they burn through too quickly for load pulling. When I was first learning I used a lumps of briquette in with the char to make the fire more responsive. The fumes just about killed me.

Have you tried Fingal Valley coal?

AALS convention 2014 still under discussion.

[jma1009]

what is 'char'?

i sort of presume it's half way between coal and peat? a form of lignite?

cheers,
julian

[steam4ian]

Julian

Char is the outcome of beneficiation of low quality coal like Lignite / Brown coal. Victoria, WA and SA have reserves of low grade coal which varies from Lignite (Victoria, Yallourn Valley) through to semi bituminous (WA, Collie).

The beneficiation in this instance produces a smokeless fuel sometime called "semi coke". It is similar to the heat beads used in grills and barbeques but with much less ash; the pellets are about the same size, say 40 mm. At SASMEE we have a small crusher linked to a tromell which grades what we crush.

Because it is semi coke we can have deep fires as discussed.

Why, when we have millions of tonnes of good steaming coal we use char I have no idea, it probably has something to do with availability. Who has room to store a semi trailer (artic)load of coal when char is produced and packed for the smaller consumers like small local hospitals?

Ian

[Deleted]

Well here's one description >>>>>>>>>>>>>>> en.wikipedia.org/wiki/Char <<<<<<<<<<<< But I thought "CHAR" was more akin to this}----------- english.stackexchange.com/questions/18152/british-usage-of-cha-char-or-chai-to-mean-tea --------------?....Which begs the question}-- have we discovered a way of using Tea to run our locos' on ??

[Jim]

Thanks for the detailed explanation regarding the char we use Ian. It's information that I haven't seen before and clarifies a couple of points such as the depth of fire we can have.
I suspect too that many grates have too high a air ration for burning char. If you have any thoughts there I'm sure I'm not the only one who'd be interested.

Hope you soon get some cooler weather in South Oz.

Jim

[steam4ian]

Jim

I have just about exhausted all my knowledge on the subject and that remaining is probably of little use and is more anecdotal.

My own loco was supplied with both a bar grate and a rosebud* grate and I was told to use the rosebud; I did have success with this, too much, but that is another story.

At SASMEE grates would be about 50/50 bar or rosebud and both seem to work equally well. Ultimately depth of fire will become more significant than grate resistance as in full size practice and then ash pan air opening can control the air.

*rosebud grate = plate with holes drilled in it using slocolme drill with the small hole at the top of the grate.

The weight of opinion in SASMEE is that the most recent chars will need more air through the grate, probably due to higher volatiles. There is another view that says grate opening affects ashing and clinkering. Time will tell.

Regarding the Bacchus Marsh char I suspect it may not be char as we have understood it but a beneficiated coal using a patent low energy process, volatiles may be higher than coal. Again time will tell.

Regards
Ian

[Deleted]

Hello IAN---- I found that "Rosebud" grate idea interesting----new one on me--- you live and learn, so they say....What diam. holes are used and what pitch are they apart, typically ??...The effect I imagine is almost like a multiple blast pipe, with the primary air velocity much faster than a conventional bar grate ??--------- Have you any photos of such items ??