Self Blocking Rail Clamps


These rail clamps are storm brakes suitable for high holding forces: from 100 to 2000 kN.

The self-blocking rail clamp even in working position starts really to work, pressing the rail sides, only if the wind force overcomes the gantry brakes capacity. When this happens and the crane tends to move, the rail clamps pressing on the rail sides with a force proportional to the wind force deducted the gantry brakes force.

The capacity values indicated in the catalogue are calculated with friction coeff. of 0,25 or 0,45 between breaking shoes and rail, since the real coeff. is much higher (approx. 0,59 – certified by TUV German register), the rail clamps have High safety factor.


Light Maintenance:
Breaking shoes are practically for the whole life, thanks to the self-blocking working principle (working only when wind force overcomes the gantry brakes capacity, with a force proportional to the wind force deducted the gantry brakes force). Jaws duration is very long (our experience is that jaws last is not less than 10 years, in some cases they have been changed after 25 years of life) minimising maintenance needs. Particular suitability to high speed cranes thanks to the free movement: the wide gap (seldom contacts) between guides and rails allows a long duration of guides.

The holding force does not decrease in the years, thanks to the self-blocking working principle. The wear of shoes is negligible and in any case does not affect on the holding force. Independence of the holding force from the fatigue deriving from heavy duty cycle (the absence of springs renders this device suitable to the continuous open/close applications). Fast opening with law power: opening is made just rising up the light weight of the calliper (not working against strong springs and wasting energy).

High tolerance:
The automatic system allows very big variation of rail width (on request, up to 8 mm). Vertical allowance of the position respect the rail of ± 12 mm is big enough to permit a fixed installation also in the middle of the seal beam (no wheels are needed).

Easy installation:
Any type of installation is possible, without need of “on trolley” realisation that requires further maintenance.

Rail preservation:
End user will take advantage from the negligible effects of wear, due to the automatic blocking working principle


Customised realisations are available like integration of stowage pins in the clamp case frame, top flange, etc.
Electric board are available.


This type of clamp is applicable in a very wide range of rail-mounted cranes and machines.

The wide capacity range (100-2000 kN) renders them suitable for the light RMG as well as for the last generation of giant Super Post Panamax Ship to Shore cranes.

These clamps are particularly flexible towards rails with wear thanks to the high allowable tolerances given by the side wedge working principle. The absence of springs and therefore the absence of fatigue is the best feature for heavy-duty application (where a strong cycling work is requested, i.e. closure at each gantry stop).

Other peculiar applications:

• High speed automated stockyard cranes
• Coal-mineral yards loaders
• Unloaders
• Stackers
• Reclaimers
• Big shipyard Goliath cranes

The installation can be done on every part of the crane.