1.
Five generations
2.
The basics
3.
Side haul railway dry docks
4.
Transfer systems
5.
Hauling machines
6.
Ship transfer machinery
7.
Chains, rollers and maintenance
8.
Bridles roller system
9.
Difficult drydocking
10
Construction procedures
11.
Restoration & enlargement
12.
Vertical lifting vs. inclined ways |

Longitudinal haul with side transfer.
The side-haul railway is selected when required by conditions
peculiar to many rivers - rivers often subject to wide ranges
of water level, with periods of low water lasting several months,
interspersed with shorter periods of high water. The vessels plying
such rivers are of necessity shallow-draft, flat-bottomed craft
of light construction, which may have to be drydocked at any river
stage. To meet the requirements, side-haul railway dry docks are
constructed on relatively steep gradients providing sufficient
vertical movement to permit drydocking at all stages. Since they
have certain inherent disadvantages, are comparatively expensive,
and are not particularly well adapted for ocean-going vessels,
they should be chosen only after careful study indicates that
other types are unsuitable.
The principal technical disadvantage of the usual side-haul
dock consisting of several cradles, each handled by one or two
parts of chain or wire rope, is that the load on any part cannot
be adequately determined, so that it is fundamentally impossible
to use an equalizing system. In consequence it is necessary to
use oversize chains or wire ropes to allow for possible overload.
The 300-ton dock designed for the French government and installed
at Dordrecht, Holland, after World War II, was designed with a
single, unitary cradle, using only two hauling chains. By this
means, the load on each chain can be readily determined, and no
differential movement of the chains can affect the load on them.
That railway, which has a transfer system, was installed to
permit production-line erection of prefabricated Rhine barges
supplied from the United States and Canada. It is useful in the
longer run for docking these craft, with the transfer system available
for those requiring extensive repair
Next: Transfer systems
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