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 Post subject: Confused operator
PostPosted: Thu Feb 07, 2013 2:43 pm 
Hi, I recently came across reference in a railroading book to maneuvers called a "Double Sawby" and Flying Switch. Can anyone help me understand what they are?


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 Post subject: Re: Confused operator
PostPosted: Fri Feb 08, 2013 12:58 am 
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Location: New Zealand
Dave,
the double saw-by is a meet and pass of two longer trains than the passing track will allow to clear. The explanation would be too lengthy to regale. So ... http://www.youtube.com/watch?v=28M1Wj1T_Jw

The Flying Switch aka "dutch drop" known to us on NZR as a "slip" is where the Loco and car is stopped short of a facing points, the Loco accelerates rapidly, eases off allowing the car to be uncoupled and the loco then accelerates swiftly. The points to a siding are then thrown after the Loco passes over and before the car so as to direct the car into the siding.

One night in the '70's in a full yard, I had the unnerving episode of doing the same and the Shunter pulled the points over, running us into a full road with the result of us unable to stop short, bashing into the stationary wagons, and then getting runted in the arse by the Guards Van that we were trying to slip past us. If care is taken and everybody knows what they are doing, and the handbrakes work, then it is an easy way to get around a car.

Probably not allowed by the OSH guys nowadays.

Chris
in New Zealand

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 Post subject: Re: Confused operator
PostPosted: Fri Feb 08, 2013 10:01 am 
Ok. Thank you! I see now. I actually saw a Flying Switch done on a short line, by some very experienced men. They also poled some of the cars into place, also. They used a large metal rod instead of a wood pole. I also don't understand what it means to "kick" cars. Bearing in mind that I want to be an engineer after I graduate, I think that I should know these terms. I actually saw someone do a double saw by (I didn't know it at the time, as I just watched the video) at a train show. It was pretty interesting to watch, especially since it was a single operator on his own modular layout. It was also neat because he didn't have DCC (Digital Command Control), just block sections and a conventional, home made walkaround throttle.


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 Post subject: Re: Confused operator
PostPosted: Fri Feb 08, 2013 4:48 pm 
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Dave,
Kicking off is simple, uncouple the wagon , short burst of acceleration of the Loco, and stop. The wagon rolls to where you want it, repeat the maneuver. On the leg (laddertrack?) a Head Shunter can get a number of wagons rolling at the same time to different tracks, another man will get the points to direct the flow. It depends on the number of tracks in the yard as to how many men are in a gang.

Beats the heck out of pushing wagons into place and backing out. Need good guys to catch the brakes, i.e. hop on the rolling wagon and apply the handbrake to bring it to a stop against the other wagons without a heavy impact.
OSH don't think that is acceptable anymore. Railwaymen thesedays have no fun like we did.
Hump shunting is along the same principle but with better control.

Chris
in New Zealand

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 Post subject: Re: Confused operator
PostPosted: Sun Feb 10, 2013 9:46 pm 
When you mean pushing the cars, that is like what we do on model railroads because we can't "kick" the cars? I also don't understand what it means to put the brake lever in the "lap" position. I know how the brakes work. They use air held in reservoirs under the cars to hold the brakes off, and when you apply the brakes (lets say a 10 lb application), some of the air is bled off into the atmosphere. when you then release the brakes, air from the reservoir in the locomotive replaces the air that was bled off. I don't get why the air in the locomotive doesn't get replenished while the train is underway. I also understand how dynamic brakes work. Was there and equivalent So to dynamic brakes during the steam era? So, what does it mean to "lap" the brakes?


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 Post subject: Re: Confused operator
PostPosted: Mon Feb 11, 2013 5:05 am 
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Dave,
If you have KD's, you can kick cars on a model railroad just like the real thing. As to your airbrake questions I think you are refering to the old style #4 or 6Sl as opposed to the 26L self-lapping brake and what ever passes for those computer-controlled things they have today.

It's quite a complex description and I'm not sure everyone wants to read it either, it's 30 years+ since I sat my airbrake and I tried to forget it right away, Haha!
Basically the lap position is the "holding" position of the Valve, this is the 3rd position on the valve quadrant, there was charging and release, running release, lap, application and emergency. Once the Engineer has made the desired application (reduction) in Brakepipe pressure and by placing in "lap" that reduction is held untill either he makes a further reduction or moves the Valvehandle into release. Usually the BP leakage will pull down the BP pressure anyway.

If that doesn't satisfy your query, PM me and we'll go from there.

As to replenishing the air on the locomotive whilst under way, that's what the compressor is for; automatically maintaining Main Res. for charging the Brake Pipe. The feedvalve or later, the pressure maintaining feature in the 26L keeps the BP(trainline?) up. By the way, the 26L is "self-lapping". I never had any use of those steam engine straight-air brakes, I guess you just used them like the train brake when moving the loco by herself.

There was a Le Chatelier Water Brake which was a steam version of the Dynamic brake, the D&RGW used it on their steam locos. Look up the Narrow Gauge Discussion Forum to get the hot oil on that.

Chris
in New Zealand

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 Post subject: Re: Confused operator
PostPosted: Sat Feb 23, 2013 2:56 pm 
I came across an old bag in the basement, and I was told that it was a "grip" from the steam days. What would generally be in it?


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 Post subject: Re: Confused operator
PostPosted: Thu Mar 07, 2013 10:40 am 
I came across reverence of helper locomotives being cut off "on the fly" what does that mean and how was it done? I plan to have a steep grade on my model railroad, and I am looking for a way to realistically model the practice of pushing trains to the summit. any suggestions?


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 Post subject: Re: Confused operator
PostPosted: Fri Mar 08, 2013 7:41 pm 
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Location: SW Indiana
:twisted: Google Search !

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 Post subject: Re: Confused operator
PostPosted: Mon Mar 18, 2013 3:39 am 
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Miner Dave wrote:
I came across an old bag in the basement, and I was told that it was a "grip" from the steam days. What would generally be in it?



I'm not certain what a US engineer might carry but I had the following in my bag...
RuleBook, Working Timetable, Locomotive Staff Operating Instructions Handbook, Overhead Traction Electrical Handbook, Semi-Permanent Train Advices, assorted favourite magazines, Not-To-Run cards, Train Consist forms, spare WHB O-rings, Pliers, two adjustable spanners, 3 sizes of screwdriver, pipe wrench, cold chisel, ball-pein hammer, square key(for doors), torch, woolen hat, gloves, cup, spoon, knife, and a thousand mile lunch. On the shunt, I only carried magazines and the lunch. Never went without a lunch, Anywhere!!

Walking home from work one night around 4-am after a long shift a patrolcar pulled alongside and the officer got out. He asked me can he look in my bag, I said no, he then asked what's in the bag so I rattled it all off for him less the lunch, he said don't be a smartarse so I opened the bag and showed him. He was quite taken back when I started to bring out the various rulebooks listed above then asked why I carried the tools: I said because I knew how to use them, unlike "some" others.

Chris
in New Zealand

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 Post subject: Re: Confused operator
PostPosted: Mon Apr 08, 2013 2:27 pm 
What is the purpose of a Jonson Bar? What does it do? What does it mean when an engineer "hooks 'em up"?


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 Post subject: Re: Confused operator
PostPosted: Wed May 15, 2013 9:57 am 
What is the definition of a "cornfield meet"? Hey Chris (USA), do the small mine steamers have Johnson bars?


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 Post subject: Re: Confused operator
PostPosted: Wed May 15, 2013 1:25 pm 
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Joined: Fri Jul 15, 2005 2:34 pm
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Location: Within 60 Miles of the Northern Anthracite Field
Yep

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 Post subject: Re: Confused operator
PostPosted: Wed May 15, 2013 5:04 pm 
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Location: SW Indiana
http://en.wikipedia.org/wiki/Johnson_Bar_(locomotive)

http://www.steamlocomotive.com/appliances/valvegear.php

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