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Re: Dynamic braking question-Chris-they did just fine.
Author: Chris Walker
Date: 05-02-2016 - 02:06
Thanks Bob2 for your detailed answer, but I had posed the question rhetorically.
You see a long time ago I cut my eye teeth running G-12's with 6sl ABV and 325 amp max Dynamics on short, heavy, under braked trains. On 1 in 48 grades where you had to use full air and DB just to hold it below the speed limit. They had a 15 mph speed restriction over a viaduct at the bottom, I fired for a few old Enginedrivers who had difficulty getting it down to that speed at the bottom too. We had no retainer valves either, only on Steam loco tenders from what I understand were used when the driver brakes were bailed off running light.
I've also had to run a way over tonnage train without DB down a 1 in 35 gradient and with 25 mph curves all the way all because some Fitter totally disabled DB on a/c of burntout grids on the front unit, instead of just disconnecting the DB. We just changed over in the middle of nowhere, Control had no idea of the overtonnage/no DB situation either. I just followed what I was taught, in accordance with the Working Timetable, releasing speed for that hill was 6 mph and I only did that once, fully stopped it on the second application for the recharge before being shoved off down again. I could easily see when a new guy would use up all his air on there with that lot. Sure would have made for an interesting stop at the bottom if the sticks weren't off for the junction too. :)
Seems the current mindset is all DB or nothing even here nowadays, but if you need DB and can't get by on air alone, and the DB fizzes out, you should stick to driving a bus.
Cheers
Chris
in New Zealand
You see a long time ago I cut my eye teeth running G-12's with 6sl ABV and 325 amp max Dynamics on short, heavy, under braked trains. On 1 in 48 grades where you had to use full air and DB just to hold it below the speed limit. They had a 15 mph speed restriction over a viaduct at the bottom, I fired for a few old Enginedrivers who had difficulty getting it down to that speed at the bottom too. We had no retainer valves either, only on Steam loco tenders from what I understand were used when the driver brakes were bailed off running light.
I've also had to run a way over tonnage train without DB down a 1 in 35 gradient and with 25 mph curves all the way all because some Fitter totally disabled DB on a/c of burntout grids on the front unit, instead of just disconnecting the DB. We just changed over in the middle of nowhere, Control had no idea of the overtonnage/no DB situation either. I just followed what I was taught, in accordance with the Working Timetable, releasing speed for that hill was 6 mph and I only did that once, fully stopped it on the second application for the recharge before being shoved off down again. I could easily see when a new guy would use up all his air on there with that lot. Sure would have made for an interesting stop at the bottom if the sticks weren't off for the junction too. :)
Seems the current mindset is all DB or nothing even here nowadays, but if you need DB and can't get by on air alone, and the DB fizzes out, you should stick to driving a bus.
Cheers
Chris
in New Zealand
