196
Molesworth’s pocket-book
Technical Report of German Railway Union.
PERMANENT WAT AND BRIDGES.
Nicking lower flange of s'eel rails generally condemned.
Angled fish plates or check plates substituted for
nicking.
Number of tons required for wear of one millimetre in
steel rails:—On level lines with easy curves, 10 to 20 million
tons; on gradients of 1 in 120, easy curves and moderate
breaking, 6 to 1 millions ; on gradients of 1 in 60 to 1 in 100,
curves of 1600 feet, 4 millions; on gradients of 1 in 40 to 1 in
100, curves of 636 feet, 1 to 2 millions.
Old steel rails may be rolled over again for light tram
rails.
Steel rails should not be of lighter section than iron •
heads might be deeper, because they will last until fairly
worn down.
Average diameter of rail height, 4-95 inches; depth of head,
1’25.; breadth of foot, 4-15; width of web, -55: angle for fish-
bed, 16° to 19°. •
Maximum length of rails from 24 to 30 feet.
Chloride of zinc most largely employed for impregnating
sleepers, creosote next; use of sulphate of copper declinin01.
Cost of chloride of zinc is from 1 to 4 of the cost°of
creosoting.
Clean, hard slag ballast is the best for sleepers. Sleepers
should be covered with clean ballast. Air-drying of sleepers
before laying is desirable. Timber is more durable if felled in
winter. Drying before pickling is desirable in the case of
creosote, but not with chloride of zinc.
Hard wood sleepers should be bored for spikes, but not soft
wood.
Check nute, spring washers, and other methods) for pre-
venting fish bolts from working loose are not satis-
factory.
Longitudinal iron sleepers, “Hilf” system, much used-
Hartwick is a failure; Battig’s system and Vauthaurin’s
longitudinal satisfactory; joint of sleepers and rails should
be together. Cross ties, 2 per length of rail on straight,
and 4 on curves. Cross sleepers, Vauthaurin’s system, most
used. Gibs and cotters abandoned for clips and hook bolts
Formation may be reduced to 10 feet for single lines and 22
fjr double lines by use of longitudinal iron sleepers.
T. se of small plates between foot of rail and the Bleepers