Page 20 - ICJ Jan 2023

TECHNICAL PAPER COLLECTOR’S EDITION

on conveyors, with the stretched wires passing
through them, are brought to this point of filling
and afterwards pulled by means of a winch to their
required place in the production line.

MODIFICATIONS SAVE LABOUR

Filling the moulds at one fixed place in the
production line, allowed a vibrating table to be
used and a water cement ratio of 0.39 for the
concrete. When the filled moulds had been drawn
up to their required position in the production line,
they were given a secondary vibration to improve
consolidation of the concrete and to ensure a
perfect bond being obtained between the concrete
and the steel reinforcement.

The modifications in the process introduced a
Relaying one of the tracks of the main line near Hitchin
on the London North-Eastern Railway with concrete simplified method of wiring ; the coils of wire are
sleepers and standard British-type chairs. carried on a truck, which is placed at the end of
the production line to be wired, and the wires are
standard main-line sleepers. Provision was made drawn off under semi-tension, which obviates the
in the lay-out of the factory and plant arrangement need of first straightening the wires. As they leave
for a second production unit, also of 20 the wire-carrying truck they are automatically
production lines, to be built without disturbing the cleaned by passing through a scrubbing box
manufacturing programme on the first production containing carborundum granules. The tensioning
unit. arrangement was also simplified; instead of
dealing with difficult loads of 60 to 90 tons at one
This extension has now been erected. The conveyor time, a machine was designed to tension a pair of
system, special to this process was designed to wires at a time in one operation.
avoid undue fatigue for the operators, as all the
individual processes were arranged to be carried
The method of manufacture allowed three minutes
out at “table height” and pneumatic apparatus
of working time per pair of sleepers during
was provided to perform any required lifting of
concreting and removal, this time factor also being
either moulds or sleepers.
maintained for the wiring process. The reduction
in labour costs using the mechanised mass-
It was arranged to concrete at one position in production process showed a saving of 88 per cent
each production line ; the moulds supported on the original cost figures.

The Indian Concrete Journal | November 2018 21