FR & WHR & WHHR News

Any gas you draw through the fire enters at ambient temperature - say 15°C - and is exhausted at the smokebox temperature of a couple of hundred degrees, after which it can do no more useful work. So the more gas you draw through the fire, the more heat is wasted that way. (And remember for every useful quantity of oxygen, you draw through about four times as much nitrogen which plays no part in the combustion but still gets heated and ultimately thrown away).

It follows therefore that you want the right amount of air to burn all the fuel but no more.

The Black Book has a useful graph showing the decrease in efficiency either side of the optimum level. The line curves either side, but fortunately at a point near the stoichiometric ratio, the curve is fairly flat on either side; in other words, a small deviation from the optimum in either direction (too much or too little air) doesn't hurt you too much in efficiency. However, if you have slightly too little, you get a small amount of colour to the smoke. If you have slightly too much air, the smoke is colourless but that is indistinguishable from having a lot too much air. Hence the advice is to fire with a slight grey haze, since that indicates you are close to the optimum ratio. If you have dark smoke you definitely have too little air and the efficiency drops off due to wasted fuel. If the smoke is colourless, you have too much air but you don't know by how much - you could be very close to the optimum but equally you could have way too much air and be throwing heat away out of the chimney by too much gas flow.

I had a turn on Sunday with ovoids, which seem to give no colour at all. Firing was not easy, since essentially you had no feedback from the chimney as to whether you were firing to right place - not even a momentary darkening of the chimney. At which point you only have the pressure gauge, water level and state of the fire to guide you.

Tom

 

Ovoids are the work of the devil. Apart from the smoke though did the loco steam ok on them?

 

That’s essentially what I was saying but you’ve said it so much more informatively.

 

It was all a bit meh to be honest. 80151 with the Pullmans, non-stop to East Grinstead with steam heating, but that’s a fairly light load with that loco. It sat at about 190-200 all the way and nothing I did seemed to make it want to go up from there. At the same time, my subjective view was that I fired far more than normal - more rounds, and more shovels per round - to the extent I was convinced that I was getting into a horrible fire with far too much coal in all the wrong places. But when we stoped, the shape was just as I’d like and it was all burnt through. It just feels you can’t get any heat out of them.

On that loco you’ve got loads in hand so not a problem. But we do the same duty on the O1 which is smaller and nearer its limit, and I think then ovoids might give you a rough trip. Whereas the O1 is brilliant on hard coal.

Tom

 

I'm glad you mentioned the pressure gauge, Steve. The state of the exhause out of the chimney can be an indicator but it is not the only one and as Tom says it can be deceptive with certain coal. When you are firing at night and are possibly blinded by the fire you cannot see the state of the chimney anyway.

Peter

 

That’s all what I would expect from ovoids. I was hoping someone had figured out a magic ingredient to add!

 

We’ve tried mixing ovoids and real coal. But the problem with that is that, with our coaling methods, you don’t get a mix, you get layers. So you spend a while firing with real coal, then suddenly it translates to just ovoids, then after a while back to real coal. So you end up with even less idea what the hell is happening!

Tom

 

At Horsted House Bridge. I was leading a walk for the Ramblers and we have just stopped. Quick photo with phone. Reduced file size above, but if you would like the full size let me know.

 

That’s a very clear exhaust

 

The issue is with people making excessive smoke whilst building fires sat in the station. It seems to be less problematic on the run. There's a good climb basically from the end of the platform at Caernarfon so you need a hot loco and fire before you set off. The loco is directly under a row of houses which doesn't help. Crews are learning how to deal with it better after a decade on Welsh Coal but these things take practice. Typically they are using hard coal mixed with ovoids at the moment but a batch this summer was particularly smokey.

 

Interesting to note that the Ffestiniog has now decided to operate short notice on Friday and is adding carriages to trains due to being "a lot busier than we thought we might be" this week.

Sent from my SM-S926B using Tapatalk

 

I've noticed that ashpans are also emptied while taking water on the run-round loop. This is directly below Segontium Terrace, so in addition to the need to build up the fire for the start up the steep (1-in-40 ish?) gradient right at the end of the platform, it's perhaps understandable that there are concerns. Not everybody likes steam trains!
It's an awkward location, but after taking water could locos move somewhere beyond the loop points towards Dinas to empty ash and build up the fire? This would probably add to the turn-round time though and there might be potential complainants there as well!

 

Above the watertower is a footpath and that's it. Doesn't mean it can't drift of course. Problem with going a bit further up the hill is that if you're not careful you'll end up with a fog across the main road.

 

It's also the practice to stand the loco on or close to the run-round headshunt point for some considerable time, while the passengers are milling around - so that they can get their photos. A good idea - but that's also directly below the houses! Unlike ashing-out and water, that's not operational and could (perhaps reluctantly) be changed, at the cost of a slightly less attractive 'experience'.

 

Bad planning really. It didn't happen, but at one point I was looking at bringing my youngest two kids to Wales this week (half term) as my wife was talking about taking the oldest away for some one-on-one time. So I had a look at the websites, and I was pretty disappointed to see that next to nothing was actually running this week. The Ffestiniog wasn't the only one either.

 

We had a trip on the FR on Tuesday, trains were very busy and an additional Woodland Wanderer had been added.
I think the Welsh half term being a week later than England has well and truly caught them out, but at least the FR has the flexibility to add trains as required.
Was also very decent weather up there too!!

 

Not all of England either - plenty of colleagues off this week.

 

On arrival at Caernarfon, you've had a loco which has been mostly coasting for the last three miles or so. So the majority of the time, the chimney will be completely clear. Majority of crews don't touch their fire, but instead elect to engage with the public. The Caernarfon Station sign on the wall is perfectly positioned for a loco. Plonk it underneath, people take photos and share it on their socials - others type in Steam Train Caernarfon....guess what the top result is? Meanwhile, the crew can have lunch having been on for about five hours before moving down for the operational bits.

With the prices as they are. Making the experience as brilliant / good value for money as possible is essential and that includes taking photographs / talking to the crew / having a look in the cab etc.

 

UK Railtours has announced a tour from London including a trip "all the way from Blaenau Ffestiniog to Caernarfon via Porthmadog". Will that be a through train or change at Porthmadog?

 

Well the info says there is a break at Porthmadog so does it make any difference?