Benefits of the ORTS Radio-Controlled Diesel-Hydraulic Grabs

Flexibility:

Like a mechanical single-rope grab the radio-controlled Diesel-Hydraulic Grabs from ORTS can operate on every crane. Just “hook on” and go. It doesn’t matter if it’s on-shore crane, mobile harbour crane, ship deck crane or auto crane (truck crane).

These grabs can work everywhere at once.

Power:

Contrary to mechanical single-rope grabs, the Diesel-Hydraulic Grabs are powerful with high closing force on the knives. They are able to handle heavy bulk cargo, like iron ore, without problems and a best grade of filling of the clamshells. With a 7.0m³ Diesel- Hydraulic Grab a rate of 250 – 300t/h in iron ore is normal. Also in clinker stone with a 12m³ Diesel- Hydraulic Grab.

Speed:

Because of the optimised construction and kinematics of the grab (especially the clamshells), Diesel-Hydraulic Grabs are fast and efficient.

Saving money:

With radio-controlled Diesel-Hydraulic Grabs the owner is saving the costs for crane equipment that is necessary to operate electro-hydraulic grabs, the costs for installation of the crane equipment, the costs for maintenance and spare parts for the crane equipment (e.g. the expensive cables).

Dead Weight and Payload:

A radio-controlled single-rope grab for an average piled density of 1.8t/m³ and with 12m³ capacity has a dead weight of around 10.5 – 11t.

A radio-controlled Diesel-Hydraulic Grab with a capacity of 12m³ for the same density has a dead weight of 7.3t.
This means for a vessel with 30t cranes on board, which has to discharge e.g. limestone (density 1.5t/m³):

Diesel-Hydraulic Grab
12m³ (capacity) x 1.5t/m³ (density) + 7.3t (grab) = 25.3t

Mechanical Single-Rope Grab
12m³ (capacity) x 1.5t/m³ (density) + 10.5t (grab) = 28.5t

The SWL of the crane for normal cargo is 30t. Considering the advice of crane manufacturers to lower down the SWL of the cranes for grab operation with approx. 15% – 20%, this means that the 30t crane has a SWL for grab operation of 25.5 – 24t.

The Diesel-Hydraulic Grab fits; the mechanical single-rope grab is too heavy.
If possible, the volume of the single-rope grab has to be reduced down to at least 10m³ before the operation can start.
The radio-controlled Diesel-Hydraulic Grab is faster (more cycles per hour) and it can handle 2m³ more bulk at each cycle.

Other advantages:

These grabs can come on board of a vessel temporarily for a new contract and be transferred to another vessel when the contract is over.

Other customers put Diesel-Hydraulic Grabs stationary in a port for unloading their own vessels. Then the shipping company can save money on the charter rates because there is no need to charter vessels that are equipped with grabs. Additional money is saved, as there is no need for foreign grabs to be rented in the harbour.

In the meantime, between the arrivals of the vessels, the owner can rent out the grabs to other companies and earn additional money.

With mechanical single-rope grabs it can happen that an unload operation of a vessel has to be stopped because of low tide in the port and the hoppers are out of reach for the single-rope grabs for some hours (as they are too high then). This is caused by the length of the closing rope, which gives a fixed working height. This working height for an average 12m³ single-rope grab is approx. 10-12m (it depends on how often the rope is reeved inside the grab).

For heavy bulk the closing rope has to be reeved more than 3 times in a single-rope grab.
With a 4 times folded closing rope the working height increases and so does the time for closing the grab.
An additional problem for single-rope grabs is that the working height also limits the minimum distance between jib-head and grab. So the crane diver has to compensate this 10- 12m working height with the jib. And lifting the jib costs valuable time.

The radio-controlled Diesel-Hydraulic grabs have been manufactured by ORTS for 12 years now. Improvements were made with help of our long-term customers. Coming with normal proper maintenance these grabs are the most effective and reliable working machines.

The grabs are in operation in the Black Sea Area, Southern Africa, the Far East, the Baltic Countries, Saudi Arabia, Australia, Europe and on board of sea-going vessels.

These grabs are available in 2-clamshell for bulk and orange-peel design for e.g. scrap. There is also a special construction, e.g. for timber logs and woodchips, in the draw. The diesel-engine emissions are in accordance with the newest Euro norm.

ORTS GmbH also specialises in other grab types, e.g.:

• mechanical 4-rope grabs
  
• electro-hydraulic grabs
  
• dredger grabs
• salvage grabs
  
• oil recovering grabs (for collecting waste-oil after accidents from the water surface)
  
• load beams (traverses) up to 100t
  
• equipment for deck cranes to operate electro-hydraulic grabs
  
• environmental protection grabs with enclosed clamshells (since 1980)

All grabs are constructed and manufactured in the workshop near Lübeck / Germany. All suppliers and sub-suppliers are located in Germany. Therefore, the grabs from ORTS GmbH are real products “Made in Germany”.
The grabs are inspected, approved, load-tested and certified by GERMANISCHER LLOYD.