“Sound barrier” – I am not an acoustical engineer, but I believe
the effectiveness of the roadbed sound attenuation comes
from the mixed materials. Doubling the thickness of a cork
roadbed does not change the sound very much. Thicker
Homasote has little effect. But mixing layers makes a differ-
ence. Each material will tend to transmit a different spectrum
of sound waves. What vibrations get passed through cork
will be somewhat different than the spectrum transmitted by
camper tape. I suspect that in the cork/camper tape mix, the
cork provides some damping and the camper tape does a good
job of isolating the sound from the plywood.
Montanan:
I use a product called Homabed [2] and it is fairly
quiet, but you can still hear some noise. There will always be
some noise, I guess. I really don’t notice it. The only time I ever
noticed any noise is when I put a camcorder on a flat car and
ran it around the layout.
J. Graffi:
I went with a foam roadbed by Woodland Scenics and
glued the track down with diluted white glue. I did not drive
the locating nails tight with the ties and made sure there was
some give. I ran the trains without ballast for a year or so, and
was impressed that there was little if any noise. I could hear the
clackity-clack of the wheels going over rail junctions and turn-
outs everywhere on the layout, even with two trains running.
Recently, I began the ballasting process and hear no difference.
Rick:
On my previous layout I had a large (3’ high) plaster cloth
mountain, and when the train went through that area there
was a disturbing unnatural roaring sound. I cut the plaster cloth
where it attached to the plywood sub-roadbed and stuffed
foam rubber between the two, then used rubber cement to
glue down the ground foam onto the foam rubber. The roar
was gone.
Prostreetamx:
Most of my code 83 Atlas flex track is mounted
on Midwest cork over Bituthene. See
The stuff
is used to weatherproof around home windows and comes in
wide rolls with an adhesive backing. I cut it into narrow strips
and put it on top of the plywood roadbed. I use adhesive caulk
to stick the cork to the base and also caulk the track. Bituthene
is very similar to Dynamat and other sound deadening prod-
ucts used in the automotive stereo industry.
Ntraker:
The best I have found is a product called Vinylbed. The
name changed recently to Flexxbed. It can be ordered directly
from the factory at Hobby Innovations.
Quiet roadbed:
.
Courtesy of Prof Klyzlr:
Foam Drum:
mrhma
.
Foam Drum II:
mrhma
.
Foam Drum redux:
.
TT&TO: Rule 91
Q.
My train, No. 24, is in a siding waiting for No. 6 to pass.
When No. 6 passes, how soon can I come out of the siding and
how closely can I follow?
A.
Check out Rule 91. First, check your timetable again for traf-
fic that may have moved up on you since you went into the
siding. Review your other orders. If all is clear, by the time you
throw the switch, get the brakeman back on, it’s going to be
about 10 minutes. By the time you get your train up to speed,
it’s almost certainly going to be 10 minutes.
Questions, Answers & Tips - 4
MRH-Nov 2014
