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Subject: 
Re: Train Stoppers
Newsgroups: 
lugnet.trains
Date: 
Wed, 8 Mar 2000 15:39:46 GMT
Reply-To: 
regult@[ihatespam]aol.com
Viewed: 
1198 times
  
On Wed, 8 Mar 2000 14:48:48 GMT, Larry Pieniazek <lar@voyager.net>
wrote:



Tony Priestman wrote:

On Wed, 8 Mar 2000, Larry Pieniazek (<Fr34wr.101@lugnet.com>) wrote at
04:10:03


A device called a derail is used. This device, which looks a bit like a switch
frog and a bit like an anvil, mounts trackside. It rotates clear, or rotates to
drop in place. When in place, it sits up about 3 inches above one rail and cars
rolling to it will have one wheel lifted off the track and then dumped on the
outside of the rail, which effectively derails the truck (the other wheel is
pulled off). Derailed cars usually don't roll much farther, hence the main is
protected.

Derails also have to be installed on the correct side of the track. If
they are on a siding or industrial track they are installed on the
rail of that track that is furthest from the main, that way the wheels
are lifted up, over the rail, and dumped on the side away from the
main.

I have an image in my mind of a thing like a switch, but it's just a
break in one rail, so that if it's open, the stock will fall off, but if
it's closed, it just looks like an ordinary stretch of track. Does this
ring any bells with anyone?

Yes. I believe this is how derails used to be done a long time ago. But
doing it this way requires actual trackwork, in that a section of rail
needs to be removed, and some very precise relaying of track (with
plates below to support the single point moving to and from) has to be
done.

This type of derail is commonly called a switch point derail for
obvious reasons. The only ones of those around here protect
drawbridges are are controlled by the drawbridge operator and/or
dispatcher. In this case the switch point derails are installed
alongside the drawbridges signals. Anyone going past a stop signal
will be derailed before hitting the bridge.

The modern device I described can be installed on an existing siding and
the installation consists of drilling 2 holes in the web of the rail,
and bolting this device on, then mounting the lever that flips it to the
side of the track.

These are usually called flip-flop derails. They are used just about
everywhere. Nearly every industry has one protecting the mainline from
cars in the industry.

The working LEGO derail design I've used in the past is to use a 1x2
brick and a 1x2 plate with 4 wide headlight holder, as used on many
Town vehicles. Attach the 1x2 plate to the top of the 1x2 brick and
then attach it to the track. Place it on the inside of the rail, so
that the 1x2 plate with 4 wide headlight holder faces the rail, with
the studs from the headlight holder actually be over part of the rail.
It will derail any cars that go over it in a somewhat prototypical
fashion. It seems to work better with normal 4 alxe cars as opposed to
2 axle ones.

It serves the same function that Larry describes, with the open end
facing away from the main line to catch anything heading that way that
shouldn't be. This would be used (I imagine) with an interlock for the
switch off the main line, so that both have to be thrown at the same
time.

I have heard of this but it's not that common in the US, most derails
are manual and depend on the brakeman remembering to throw them. There
are, of course (always!!) exceptions. Derails are (almost?) never used
to protect interlockings, just sidings.

Many derails around here are connected to mainline switches with
electronic locks. You have to throw the switch first before removing
the derail, otherwise the switch won't move if you get the derail
first. There are also electronic timers which don't allow you to throw
a switch after a certian amount of time has passed after starting the
timer on the switch, this also protects the main, but in a different
way. Often times these electronic timers and locks are installed
together.

Interlockings and drawbridges are sometimes protected by "smashboards"
which don't actually protect, but do offer evidence that the engineer
ignored the signal indication. (a smashboard is just as it sounds, a
mechanism to put a board into the path of the train when a signal has a
certain indication, such that the train will smash it if it proceeds
through)

The only smashboard, if you can call it that, at our drawbridges are
their counterweights. Hitting those will indeed indicate that you have
passed a stop signal, although at that point, it probably won't matter
much to you anyway.

At low density interlockings you sometimes saw gates across the lower
density track. This is less common nowadays as most interlockings are no
longer human tended, they are controlled from the CTC board, hundreds of
miles away.

In and around the steel mills here, there are literally tons of these
gates protecting interlockings. One has to get down off the engine,
look for approaching movements, then use the crank on the gate to
swing it over the path of the crossing track. The gates look very much
like normal road crossing gates wtih reflective tape and red
(non-flashing) lights.

BTW, several of the industries around here have the spring loaded end
of track bumper blocks. I guess they got tired of their other ones
getting knocked off the track all the time.

--
Larry Pieniazek - lpieniazek@mercator.com - http://my.voyager.net/lar
http://www.mercator.com. Mercator, the e-business transformation company
fund Lugnet(tm): http://www.ebates.com/ ref: lar, 1/2 $$ to lugnet.

Note: this is a family forum!

Jeff Christner

Visit Sixby Fire Tech at - http://members.aol.com/regult/

Help support my LEGO habit. Ship by rail.
Visit http://www.nscorp.com/ to find out how.



Message has 1 Reply:
  Re: Train Stoppers
 
At the edge of my memory, I can remember, as a kit, hearing a news story about derailers being stolen. It made the news as the items stolen were explosive in nature. I assume it would be a small charge which would be set off by the train/carriage (...) (25 years ago, 8-Mar-00, to lugnet.trains)

Message is in Reply To:
  Re: Train Stoppers
 
(...) Yes. I believe this is how derails used to be done a long time ago. But doing it this way requires actual trackwork, in that a section of rail needs to be removed, and some very precise relaying of track (with plates below to support the (...) (25 years ago, 8-Mar-00, to lugnet.trains)

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