Model Forum / General / Railroads / May 2007

   Barring mechanical failure, cars come off rails for two reasons: inertia
or trackwork.  A car that is too light is unable to resist external forces
pushing against it.  According to NMRA recommended practices, a 50' boxcar
should weigh 4.5 oz (135 g) and an 85' passenger car should weigh 7 oz (210
g).  Here is a link if it helps: http://www.nmra.org/standards/rp-20_1.html.
It's only a guideline and I mention it as a consideration.

   Trackwork is another issue which may cause cars to derail.  I've noticed
it particularly at train shows whose modelers work with modular exhibits.
For that matter, I've noticed it at railway crossings watching a loose rail
move an inch or more as engines and cars pass over it.  It doesn't leave you
with a good feeling.  Well planned and well laid trackwork is a must if you
wish a smooth running layout, particularly if you intend to let the train
run for extended periods.  It wouldn't hurt to befriend a finish carpenter
and electrician.

   I perused your model railroad pictures and you have done a lot with a
confined space.  In theory, one could use such a layout to demonstrate the
different scales.  Larger scales are more forgiving of small mistakes.

Cheers,
John

Properly laid track rarely derails trains, even cheap trains!

I suggest you review the quality of your baseboards and track laying.

That's not to say you've got it wrong, perhaps you've bought a rogue
trainset, but from the limited comments you've made I suggest you buy
some of the "how-to" books from Kalmbach and the like and consider the
bits relating to common track laying mistakes.

Regards,
Greg.P.

Step one is to decide if the derailment is caused by track or by the
rolling stock.  As a general rule, if different cars derail at the same
place, its a track problem.  If the same car comes off the track at
different places, its a rolling stock problem.
 Track wants to be flat, no bumps or bent up places. Fix any bumps at
the joints in your road bed. Check all your track for kinks between
pieces.  Use a straight edge to check straight runs, and eyeball all
your curved track and turnouts, looking for places where the track fails
to curve smoothly.  Nail all your track down to the roadbed.  Get a
three point track gauge and check the gauge of your rails everywhere.
 Track nails if driven down too hard can bend the ties and pull the
rails out of gauge.  Track joints want to be smooth.  Run your fingers
over all your track and fix any rough spots.  Make sure the rail joiners
are properly set at each joint.  Sometimes the bottom rail flange fails
to slide inside the rail joiner, causing a bump.
  Get the NMRA gauge and check all your turnouts.  If the flange ways
between the stock and the guard rails are too shallow or too narrow  you
get derailments on turnouts.  Feel the points of each turnout and file
down any point that feels to rough.  Make sure your turnouts throw all
the way, for both positions.  A partly thrown set of points that doesn't
 fit firmly against the stock rails is trouble.
  If you have grades on your layout, make sure you have a smooth
transition from the level onto the grade.
  Rolling stock wants the gauge of all the wheels checked with the NMRA
gauge.  Out of gauge wheels can be twisted and moved wider or narrower
with finger pressure.  Check the screws securing the trucks.  Both
trucks need to swivel freely.  One truck should be as tight as possible
(short of binding) and the other truck should be a quarter or a half
turn looser.  This permits the looser truck to tilt sideways and keep
the wheels on the track.
  Get a small scale and weigh all your cars.  I stick with the NMRA
weight recommendation, one ounce plus 1/2 ounce per inch of car length.
The important thing is to have all the cars in the train weighted to the
same standard.  If you have some cars light and others heavy, the  heavy
cars tend to pull the light cars off the track. Add weight to light
cars.  For "house cars" where the weight is concealed, I use any old bit
of metal scrap I have hanging around.  I secure all my weights with Dow
Corning silicone bathtub caulk.  The stuff that smells like vinegar as
it dries.  For open cars like hoppers and flats you want to use lead, to
make the weight as small and easy to conceal as possible.  Tire stores
often will give old lead wheel weights away.  Hardware stores sell sheet
lead flashing that is easily cut with sissors.  Lead shot can be  fitted
into odd places like the center beam.
  Clean all your wheels.  A surprizing amount of "wheel cheese" can
build up on them. I have seen wheels with crud on the tread built up to
the height of the flange.  Goo-gone is my cleaner of choice.  Moisten a
bit of paper towel with Goo-gone, lay it on a spare piece of track.
Then run the car back and forth on the towel and watch the black crud
build up on the paper towel.
  Check coupler height.  You can buy a Kadee coupler height gage or you
can make one, using your NMRA gauge as a reference.  Low hanging
couplers mean the glad hand under the coupler is low, and will catch on
turnouts and crossings.  Low body mounted couplers can be raised by
adding #6 flat washers under the trucks.  You want the coupler height to
be uniform thruout the train.  High and low couplers will spontaniously
uncouple, an event as irritating as a derailment.
  Watch the coupler action as the train enters a curve.  A long car
coupled to a short car can cause side thrust while the train is on the
curve, which levers one car or the other off the rails.  Shorter rolling
stock (40 foot boxcars) and shorter locomotives with four wheel trucks
take curves better than 80 foot passenger cars and big steamers.    18
inches is the minimun radius in HO, and some long rolling stock needs
broader curves to stay on the track.
  Derailment in HO is never accidental.  It's always a flaw in either
the track or the rolling stock.  Take a zero defects approach to
derailments, find and fix the cause of each one and soon your trains
will run derailment free for days.
  Good luck.

David Starr

You can always add weight to cars that are too light. Re-railing sections
can work wonders also if you have especially troublesome parts of a layout.

Good ho loco at good prices,
Proto 2000 GP7 $30 us$ at train world
Athearn locos Rtr about $55 us good value

www.trainword.com

What train set did you buy and what brand of loco if it a proto 2000 loco
some of the problems can be due to cracked gears, ask your neighbour to
bring over some loco or check out your layout. it good to  have friends
close by.

Anthony