• Steam train failed to proceed.

  • Discussion about railroad topics everywhere outside of North America.
Discussion about railroad topics everywhere outside of North America.

Moderators: Komachi, David Benton

  by David Benton
 
This is probably aimed at John the Fireman, but anyone s input is appreciated.
A few weeks ago , My 4yo son and I went for a ride on the Weka Pass Railway
https://wekapassrailway.co.nz/" onclick="window.open(this.href);return false;
We were touring in a motorhome, and I just happened to juggle our schedule so we arrived in Waipara the night before the train ran. Imagine my partners surprise upon waking up in a railway station carpark , with a steam train due to run that day !
Around 8 a.m, I noticed smoke rising in the depot, about 1 k.m away. That confirmed we would be steam hauled. Train due to leave at 11.30 a.m, we drove down to the depot around 10.
The steam loco appeared to be running well( to my amateur eye ), a bit of smoke rising straight up out of the chimney,and a valve behind the chimney blasting off a bit of steam every so often. I took this to mean the loco had a full head f steam , and this was the safety valve popping off.
Shortly, the loco backed onto the train , running perfectly.
We returned to the station , got tickets , and waited for the train to appear . It came around the corner, and pulled up , emitting all the sounds and smoke i would expect . We boarded and set off.
After about 10 minute and maybe 2 -3 k.ms (upgrade), we came to a sudden halt. The message over the pa was the driver was having trouble getting water to the boiler. After about 5 minutes we set off, the problem seemingly fixed. We came to the photo run by point, and the train stopped. We all climbed out , and climbed the hill to get a photo .
It was not be. It was soon obvious all was not well with the loco. Thick brown smoke was just barely rolling out of the chimney, The driver yelled out he couldn't get steam pressure up . It looked to me like either too much coal, or not enough air getting in. One of the crew grabbed a spanner, and carefully opened the firebox(?, the one at the front under the chimney) up , had a look and said something I didn't hear to the driver. I think he shook his head , but couldn't tell if he meant he could see what was wrong , or didn't know what was wrong.
The decision was made to call the back up diesel loco , which came up behind us , and pushed us for the final 6 k's or so . Unfortunately my son got quite upset at this stage , and I wasn't paying much attention , but I think the steam loco was assisting a bit. When we walked past the steam loco , it seemed to be back to steaming normally.
Any ideas what could have caused this? I have some photos and videos , which i might post later.
  by Benny
 
Sometimes bad quality coal melts on the grill and forms a coat that prevents fire breathing. Fireman needs to break the coat and clean the grill. As the water injector normally works with residual steam, in case of low steam production because of bad firing, it can be used the emergency pump.
It's only my impression but seems that crew was not very experienced.

Ciao :wink:
  by David Benton
 
Benny wrote:Sometimes bad quality coal melts on the grill and forms a coat that prevents fire breathing. Fireman needs to break the coat and clean the grill. As the water injector normally works with residual steam, in case of low steam production because of bad firing, it can be used the emergency pump.
It's only my impression but seems that crew was not very experienced.

Ciao :wink:
Thanks Benny. From my amateur eye, it did seem like to much coal was been put in the fire. However it could be lack of air , a blocked grate as you describe would cause the kind of smoke I saw.
No one seemed to know what was going on , so perhaps they were missing some more experienced crew , they are all volunteers, of course.
The addition of the diesel made it more interesting to me, though we did miss the photo runby.
  by Benny
 
An old steam driver, Mr Tessitore, told me that unexperienced firemen tend to fulfill too much the fireplace instead of cleaning the grill when there are firing problems so the two facts should be happened at the same time.

Ciao :wink:
  by johnthefireman
 
Difficult to tell without having been there or without more technical information, but it could indeed have been bad coal or over-firing as already suggested. "Thick brown smoke just barely rolling out of the chimney" would seem indicative of a poorly burning fire. However, either of those could probably have been cured by cleaning the fire rather than failing the loco - it's embarrassing but not actually that uncommon to have to stop occasionally to brew up if the fire is not burning well.

A leaking tube or a weeping firebox stay could make it virtually impossible to keep up pressure. In the former case the fireman would probably have seen the escaping steam when he opened the smokebox door, and in the latter he would see a dead patch in his fire where the stay was leaking. I've experienced both.

Without steam pressure not only can the loco not move, but it is also impossible to put more water into the boiler. Benny, I've never worked on a steam railway loco that has a mechanical pump to supplement the injectors, so if we can't get enough pressure to keep the water level up we have to throw out the fire on a coal-fired loco or shut off the oil supply on an oil-burner. I know some very early locos had mechanical pumps, but more modern British, South African and East African practice seems to have been only to use injectors - every loco would have at least two of them, so if one failed the other could still be used. Actually some East African locos had three injectors. I've fired steam tractors with mechanical water pumps.

Incidentally, most firemen hate photo run-pasts. The punters want you to produce lots of thick black smoke for their photos, so in fact you have to overfire at that point (but not as early in the process as seems to have happened in this case) and close the firehole door to reduce air flow. This buggers up your fire with a thick mound of un- or partially-burned coal and you have to fix it again after the run-past. If you're doing a series of photo run-pasts in quick succession it compounds the problem. It goes without saying that a good fireman does NOT normally produce thick black smoke - we are taught to fire "light and bright" or "little and often" and to have a thin grey haze above the chimney.
  by amtrakhogger
 
Benny wrote:Sometimes bad quality coal melts on the grill and forms a coat that prevents fire breathing. Fireman needs to break the coat and clean the grill. As the water injector normally works with residual steam, in case of low steam production because of bad firing, it can be used the emergency pump.
It's only my impression but seems that crew was not very experienced.

Ciao :wink:
Would that be known as a "clinker?"
  by johnthefireman
 
amtrakhogger wrote:Would that be known as a "clinker?"
Indeed it would. Sometimes it manifests as huge chunks, or slabs as big as paving stones, but at its worst it can be almost a solid layer covering the fire bars of the grate. It can be a real bugger cleaning it out at the end of a shift, or whilst trying to repair the fire en route.
  by David Benton
 
Thanks John.
I am thinking a leaky tube could be most likely, thinking back, the decision to call for the diesel was made as soon as they opened the smoke box door. Possibly the overstoked the fire thinking that was the problem.
Would that repair require a re cert, the loco was up and running for the next run 2 weeks later.
  by johnthefireman
 
A tube is not part of the very fabric of the boiler so it doesn't usually affect the certification of the boiler as a whole. It probably has to be repaired by a fitter who is officially certified to do so, and the boiler would probably then be hydraulically and steam tested by a boiler inspector, but it's not a full scale boiler recertification. A couple of weeks sounds like a reasonable timescale, expecially if it is being done mainly by volunteers who are not full-time on the job. It usually involves some simple but tedious tasks such as removing (and later replacing) the front plate of the smokebox and the spark arrestor and draughting gear in the smokebox, cutting out the tube itself, preparing and fitting a new tube, and removing, blanking off and then later replacing all the boiler fittings in order to do the hydraulic pressure test. Once you've got all that kit off the loco you usually inspect all the tubes and try to replace any that look a bit dodgy to save you having to go through the whole process again. Also, depending on when the tubes were last replaced, if several tubes start leaking one after the other it might be a sign that they are reaching their sell-by date and better to replace the whole lot. Incidentally, there are short cuts. If the tube lines up with the smokebox door you can get it out through the door without removing the front plate. Depending on the position of the tube, I've also seen a fitter use a gas torch to cut a small hole in the front plate to get the tube out, rather than removing the plate. After sliding the new tube in, the hole was welded closed, ground smooth, given a coat of paint and the loco was as good as new.

Of course the official regulations would vary from country to country. In South Africa a steam loco has to be issued with a roadworthy certificate before each trip, and that includes sign-off from the fitters but also from a boiler inspector. The certificate is valid for 48 hours and then a new one has to be issued. The loco has to go on to an inspection pit for this, but it is not a long process, with a few dozen things that have to be checked. It can all be done in an hour or two.

Depending on how bad the leak is you can keep going but it's hard work for the fireman. The scenario you put forward is plausible - a leak in the tube followed by overfiring to try to maintain steam pressure, leading to an over-full fire which then wouldn't burn properly, leading to the brown rolling smoke that you describe.
  by David Benton
 
Thanks John.
Here is a video of the train pulling into the station, when I would have said it was running correctly .
Apologies for the poor quality on my phone camera.
https://youtu.be/0PWr3ioyU2s" onclick="window.open(this.href);return false;
  by Benny
 
johnthefireman wrote: Without steam pressure not only can the loco not move, but it is also impossible to put more water into the boiler. Benny, I've never worked on a steam railway loco that has a mechanical pump to supplement the injectors, so if we can't get enough pressure to keep the water level up we have to throw out the fire on a coal-fired loco or shut off the oil supply on an oil-burner. I know some very early locos had mechanical pumps, but more modern British, South African and East African practice seems to have been only to use injectors - every loco would have at least two of them, so if one failed the other could still be used. Actually some East African locos had three injectors. I've fired steam tractors with mechanical water pumps. .
Well, I'm only a railfan, but seems me that FNM 200.05 and probably also some FS locos had a handy mechanical pump apart the classic injectors. Remember that the last new steam locomotives for FS were built in 1929.
This pump was only for emergency purpose, just to avoid the melting of the fusibile plug during the throwing of the fire. Surely in a big loco it's impossible to use and so it's omitted.

Ciao :wink:
Last edited by Benny on Mon Nov 20, 2017 1:17 am, edited 1 time in total.
  by Benny
 
amtrakhogger wrote:
Benny wrote:Sometimes bad quality coal melts on the grill and forms a coat that prevents fire breathing. Fireman needs to break the coat and clean the grill. As the water injector normally works with residual steam, in case of low steam production because of bad firing, it can be used the emergency pump.
It's only my impression but seems that crew was not very experienced.

Ciao :wink:
Would that be known as a "clinker?"

Frankly I don't know the English term, in the Italian railroad slang it's "crosta", that means crust.
A Swiss driver that worked on the Luino line before electrification told that, if you know that coal is bad, you can put a coat of ballast on the grill, so fire can breathe and ballast, because of the high temperature, produces lime that helps grill cleaning.

Ciao :wink:
  by johnthefireman
 
Thanks, Benny. Don't worry about the terminology - we can supply the English terms. I was interested to hear from you that your last new steam engines were built in 1929 - in Britain it was 1960!

To be pedantic, I need to correct myself on leaking tubes and add that the leak can be from the tube itself or from the superheater elements inside the large (flue) tubes. If it is the superheater element leaking then steam will only be present when the regulator is open; if it is the tube, steam will be leaking all the time.
  by johnthefireman
 
It's quite possible that a 1909 loco wouldn't have a superheater. In South Africa I think that was about the period when superheated locos were being introduced.