On the day after Thanksgiving, 2005, I
finally started construction of the giant four-track, six-tier helix that
connects the two levels of the railroad. While still in progress as of
this writing (December 2005), progress is good. My good friend Walt has
helped tremendously - this is a job that would be almost impossible for
just one person, I think. My wife Denise also lent a helping hand as
construction has progressed.
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the layout's "Zero," or starting, elevation
to Construction Methods
you see most of the hardware required to build this baby - over
1000 (that's one thousand) 5/16th nuts and nearly three
hundred each of flat washers and fender (extra-large outside
diameter) washers. They're laying on my helix template, which will
be the bottom tier in the finished helix. Not shown are the 36
5/16" threaded rods that will suspend the helix from the
ceiling. Each tier of the helix will require two sheets of
1/2" plywood - the largest radius is 42 inches. With six
tiers, that's twelve sheet of plywood. Add to that two 3/4"
sheets of plywood for the main framework and you've got most of
what it took to build this helix.
Walt is marking out the curves for one end of the elongated helix
on the main suspension framework. The basic approach for
construction is to suspend the subroadbed from a framework
attached to the basement ceiling. The threaded rods I mentioned
above are the suspension members. Different levels for the helix
will be adjusted to proper height using nuts threaded onto the
rods. The rods are suspended from a main framework that looks just
like one of the tiers of the helix, except it's made from 3/4 inch
plywood rather than the tiers' 1/2 inch plywood.
This will get
clearer as you look at the photos below.
Walt is drilling the locations for the suspension roads in all
tiers of the helix at once. All rod locations were marked on the
template, and then all the pieces are stacked, aligned and
drilled. This way we know the rod holes will all line up in the
assembled helix. The lighter-colored thicker piece of plywood just
below the template is the main framework.
I didn't put a picture of us
cutting the helix sections from sheets of plywood - that would
have been pretty boring!
we drilled all the rod holes, we assembled the main suspension
frame and installed it near the ceiling. We temporarily supported
it while adjusting it's final location to the track plan, then
began constructing the simple mounts you see here.
The mounts are constructed of
scraps of 1/2" plywood, with a few having 2X3 legs. The legs
are just screwed to joists, and a horizontal bar is attached to
those under the framework, neatly supporting the frame while
allowing for a little bit of adjustment in the helix position.
view of some supports. Their construction is quick and dirty, but
sturdy and flexible enough to allow for varying reaches across
joists - whatever span is required.
When the rest of the helix
framework is assembled and I'm certain everything aligns properly,
I'll trim the excess off all the support legs and joist ends.
is the main suspension framework completely installed and ready to
support the helix itself.
suspension rods, all 16 of them, are installed on the nearest
semi-circle, and the top level of the helix is installed. The
second level is mounted onto the bottom of the rods but not yet
raised. All tiers except the lowest will be run clear up to the
top of the suspension rods to allow tracklaying on the lowest
level. As tracklaying progresses, additional sections of the helix
will be lowered into position and tied to completed sections to
allow tracklaying to proceed around the helix from bottom to top.
That means all four tracks will be laid at the same time on each
level, even though some of those track won't be used for several
years. They will be tested thoroughly, however!
photo shows the details of the suspension assemblies. Briefly: The
rods protrude upwards through the 3/4" main suspension
framework, where a nut carries the weight of the helix below.
Between the nut and the plywood is two fender washers, to help
distribute the rod load into the plywood. A second nut is added,
acting as a jamb nut against the first to prevent the nut from
slowly turning on the rod (which would allow the entire helix to
go out of alignment). A standard washer, then two more nuts, are
used to "clamp up" the rod in the plywood framework,
effectively locking the rod into the plywood. This is repeated for
each level of the helix, except that the fender washer is on the
bottom and the standard washer is on top, and only one fender
washer is used instead of two. The fender washers go on the bottom
on the track tiers because the plywood load is going into the rod
below the plywood, rather than into the top of the plywood as
happens on the main suspension framework.
tiers are now run up to the top of the rods in this view from near
Laurel. This is the point construction is at as of December 20th,
2005. As the helix progresses, more detail will be added here.
the helix tiers have been installed in this shot from mid-January.
You can see three stacked at the top of the helix, with the lower
two in place and cork roadbed being installed on the top-most
two tiers that in place. The roadbed on the upper tier is pinned in
place for the glue to dry. The two tracks that curve to the right
towards the back are the Wyoming Mainline tracks, while the one that
goes straight off to the left is the Frannie Cutoff that will
connect to the NP Mainline at Laurel. Since the second deck is some
years from construction, I'm installing a temporary connection that
will tie the Frannie Cutoff into the track that leads to Glenrock on
the lower level. That way the NP Mainline will connect with the
remainder of the layout, making it available for early operations
(which I suspect will commence after most of the Wyoming Mainline on
the lower level is laid). It will make for a strange station
sequence, but not too bad because the NP Mainline will simply
represent the CB&Q east of Glenrock. It will assume its primary role
as the NP Mainline (while still serving as the CB&Q east of Orin) in
is now one completed tier of tracks on the helix, save for final
wiring. There are only three track here because the Cody Branch, the
fourth helix track, leaves the helix in the back on the next tier
up. For this one tier I've used about 30 pieces of flextrack.
looking at the test train from the back corner of the layout,
standing right next to where Cody will be located. The train is to
test both the track and the pulling power of the loco. I'm pleased
to report that the trackwork is good so far, and the loco pulls a
respectable train up the grade. Photo is early February 2006.
in case the trackwork is slightly less than perfect in one or two
spots, I'm adding rerailers in each track on each straight section
in the helix. Better safe than sorry. The loco is a new Spectrum.
how did we run all those nuts up and down those rods without going
crazy? With the help of a rubber sanding disk holder and an electric
drill! Without the sand paper on the disk, the rubber was able to
grip the edge of the nut enough to turn the nut, running it quickly
up or down the rod as required. Otherwise I'd still be threading
those nuts into place!
each tier, the roadbed for all tracks is laid, then sanded smooth.
After that track is laid and I moved on to the next tier.
the end of the second tier climbing upwards, the Cody end of the
Cody branch enter the helix on it's climb to Powell on the top deck.
for the lead into the helix from Cody has been laid. Even though the
threaded rods are about 16 inches apart on the outside edge of the
helix, I still had to be very careful positioning the Cody lead-in
to avoid having trains side-swiping the rod to the right of the
lead-in in the future.
Power is delivered to the helix tracks on each side of ech tier via
sub-feeders tied in to the track feeders themselves via terminal
strips. The strips are each eight connector to allow for two feeders
to each of the four tracks. Feeders are telephone wire (22-gauge, I
think) soldered to the track.
which are 18-gauge thermostat wire, get their power in turn from the
main bus, a 12-gauge stranded wire. All sub-feeders are fed down
underneath the lowest tier of the helix, where they tie to the buses
via two six-position terminal strips (I used two six-position strips
instead of one twelve-position because the twelve-position strips
are about four times more expensive than the six-position ones)
up at the bottom of the helix we see a scene like this. The fender
washers carry the load of each tier through the nuts and into the
threaded rod, which then carries it up to the 3/4-inch thick
suspension frame at the ceiling. If any area needs the grade tweaked
a bit to even it out, I can simply loosen the nuts and screw them up
or down a bit.
completed helix, seen from the door to the train room on 22 November
2006. Testing is complete, and trains run smoothly up the entire
length of the helix.