Towing Tank Facility - nptel - Indian Institute of Technology Madras

Hydraulics Prof. B.S. Thandaveswara
The carriage has two speed ranges,
(i) 0.02 m s -1 to 0.50 m s -1
(ii) 0.50 m s -1 to 5.50 m s -1
In the low speed range it can be operated by a low duty D.C. motor (manual control
only), whereas in the higher speed range it can be operated by a heavy duty D.C. motor
fed by a Ward-Leonard set, (both by manual and electronic control) and the A.C./D.C.
power supplied via overhead bus bars. The approximate speed of the carriage is
indicated on a speedometer fixed in the panel on the carriage.
The towing carriage is provided with braking system for stopping at any position in the
towing tank. Also for safety purposes, emergency braking rails are provided at both the
ends of the towing tank, which retard the towing carriage at 10 m s -2 .
For Testing of ship models in shallow water, the observation bridge and the measuring
frame can be lowered in the centre of the towing carriage.
Calibration of Flow Meters
Flow meters such as pitot tubes, pilot cylinder, and current meters are rated before
being put to use. For example, in the case of current meters, it is necessary to
determine the constants which establish the relation between the number of revolutions
Indian Institute of Technology Madras