Ipsum

Jack Model 2510-xxD-x-H-x     ("H" = Hook)

These jacks come with a “lifting hook” instead of the lifting arm. The hook holds and lifts the tank shell from the bottom edge of the plate. Welding of lifting lugs and fend-off lugs is eliminated and so is the need to test and repair tank shell plates after removing the lugs.
These jacks come with a “lifting hook” instead of the lifting arm. The hook holds and lifts the tank shell from the bottom edge of the plate. Welding of lifting lugs and fend-off lugs is eliminated and so is the need to test and repair tank shell plates after removing the lugs.
Jacking equipment with lifting hook is denoted by the “H” in the Model code.

Procedure for fixing next shell course and removal of hooks is explained below :
The tank is lowered down using jacks, to sit on newly erected shell ring leaving root gap as required. To do this, the jacks are lowered down by about 70 mm. At this time the lifting hooks will not lower down along with jacks, since their downward movement is obstructed by the new shell ring. Now one by one, using a crow bar, the shell plate (which is held by the lifting hook) is wedged towards the front (towards inside of the tank) so as to free the lifting hook and allowing the hook to drop onto the jack.