The Track
Wheel
Standards
The track at Gilling has evolved over the years since the club's inception in 1983 both in it’s layout and method of construction. The railway consists of an up and down main line loop of approx 404 yds. There are two sizable shunting yards and one smaller one. The main lines and some other track branches take 71/4" gauge traffic, 5" and 31/2". The shunting yards and underground storage is all 5"gauge. The original track circuit used aluminium flat bottomed rail spiked to Jarrah timber sleepers which were nailed to longitudinal battens to give some stiffness to the track formation. The battens proved to be the Achilles heel of this construction as rot eventually set in despite being well soaked in creosote. Therefore, a few years ago they were replaced, sections at a time, with a cast concrete track bed, with alternate sleepers secured to the concrete with Raw plugs and wood screws. The concrete track bed is 15” wide and approximately 3”- 4” deep, expansion joints are fitted at intervals to avoid cracks developing. Before casting, hardcore is forced into the ground to stabilise the earth in that area as a lot of the ground is fine clay that is unstable when wet.
Before laying track, a concrete kerb
is cast alongside the trackbed to retain the ballast and provide an edging
for
the surrounding grass. The track panels are made up using 4 or 5 metre lengths of
aluminium rail. For the curves, the inner rails are shortened by a calculated amount
and all the rails are rolled to something like the correct radius. All the fishplate
bolt holes are drilled before assembling the panels. The sleepers are precision
sawn from full size Jarrah (or similar hardwood sleepers) and jig drilled with undersize
holes to take the spikes. It is our practice to spike just one rail firmly to the
sleepers at the assembly stage, leaving the spikes on the other three rails a little
loose to permit easy lengthwise adjustment of the rails on site to equalise the
rail gaps and to give greater flexibility to adjust the line of the track. It was
decided, in addition to screwing alternate sleepers to the concrete, to bed each
sleeper on Aquaseal roofing felt adhesive to provide a useful anti-rot layer under
the wood and prevent small particles of grit from working in between the sleepers
and the concrete.
To
provide a better bond for the adhesive, after rubbing down the concrete to remove
any slight irregularities, the concrete base was coated with Febprufe bituminous
liquid membrane. Finally, ballast is applied, which in this method of construction
is purely cosmetic, the earthworks can then be tidied up and grass sown.
This method of construction was more finely honed for building the extension in 1996 – 1997 and for those interested in greater detail we suggest you read the articles in “Engineering in Miniature” March & April 1998 also issues 13 & 15 of “Turnout” the GL5 magazine. These also show photographs of construction methods. The yards use the same method of construction, though the concrete beds are wider to encompass several tracks, also point-work sits on ‘Y’ shaped beds so that all sleepers are supported at all times.
The main line, consisting of the up and down main lines each consist of just over 400yds. (The six foot way is 404yds.)The steepest main line gradient is 1 in 80 and the minimum radius curve on the railway is 45 ft..
The picture at the right shows relaying operations by the method described above. Formerly that part of the original track was laid on heavy longitudinal wooden battens but they rotted in spite of every treatment.
Visit the track construction picture gallery
There are some limitations arising from the track dimensions and line-side equipment.
The main one of these is wheel dimensions given below.
Wheel Standards
All locomotives must comply with the standards shown below
Dimensions must be at or below
Also note that footrests on driving trucks MUST be 1" above the rail head for clearance above point covers.
| G | B | W | F | D |
| 3 - 1/2" | 3 - 9/32" | 13/32" - 7/16" | 1/16"- 5/64" | 1/8" |
| 5" | 4 - 5/8" | 9/16" | 3/32" | 5/32" |
| 7 - 1/4" | 6-13/16" | 13/16" | 1/8" | 3/16" |
