Taavura Deck Lifter

General Description:

The Deck Lifter is designed to raise & lower the lift-able decks in Ro-Ro ships (particularly PCTC ships) in a much quicker, more efficient and cost effective way than the standard methods.
The Deck Lifter is a highly maneuverable, compact and robust vehicle that measures only 3 m X 6 m. There is excellent all-round visibility for the operator sitting in the cabin
Two sets of hydraulic bars are attached to the vehicle:

Four telescopic cylinders are attached to the Deck Lifter frame for raising and lowering the deck panels. 
Four stabilizers secure the Deck Lifter to the ground while it lifts the deck panels.
The Deck Lifter controls incorporate “easy of use” principles making it very easy to operate. One joystick controls the telescopic cylinders and a second joystick moves the stabilizers. A PLC display provides the operator with the required information.
The Deck Lifter has been approved for use by DNV (Det Norske Veritas).

Specifications:

The main specifications of the Deck Lifter are:

Technical specification:

All the technical information in this document is based on a preliminary design and may ultimately change.

 

Table size 
5,950 mm(L) x 2,950 mm (W)
Lifting height
(top of table)
Upp. Level
5,300 mm ± 70mm
Low. Level
1,980 mm
Table stroke
3,320 mm
Lifting speed
2 m/min (Approx.)
Lifting capacity
25 tons
Overall size
5,950 mm (L) x 2,950 mm (W) x 1,980 mm (H)
Gross vehicle weight
10,000 kg (Aprrox.)
Wheel base
3,410 mm
Min, turning radius
7,300 mm
Traveling speed
Max 15 km/hr
Transmission
Hydrostatic drive, from 0 to 15 km/hr continuously, both directions.
Engine
Deutz type diesel engine, low emission , turbo charged
Type
F4L912
Max. power
63 hp @ 2,300 rpm
Displacement
3,770 cc
Tire
Front
255 / 70 R 22.5
Rear
255 / 70 R 22.5
Steering
2 front wheel steering
Hyd. Pump
Type
Cast - iron double gear pump
Capacity
~ 110 cc/rev
Working pressure
~ 220 kg/cm2
Hyd. Cylinder
Lifting cylinder: 4 telescopic, multi stage
Jack cylinder: 4, with self aligning pads
Location of control panel
Inside driver’s cabin
Battery
DC 12 V, 165 Ah
Hyd. Oil tank capacity
~  500 liter

Hydraulic system :

The Deck Lifter has three separate circuits which consist of three pumps that are mounted on the diesel engine. All the pumps use a single high capacity oil tank (500 l).

  1. Lifting circuit: The lifting circuit is operated by a double gear pump made from cast iron.
    It consists of four telescopic cylinders, each of which has a linear encoder on the outside of the tubes in order to send its exact location to the controller.
    Using a closed loop procedure through a set of proportional valves, the exact amount of oil is delivered to each cylinder based on the reading from the encoders. This enables the frame to move up and down while keeping the panel completely steady.
    The stabilizers are also controlled by the lifting circuit.
  2. Driving Circuit: The driving circuit is operated by a hydrostatic transmission and it consists of a set of piston and motor pumps. The motor drives the rear axle via a one meter long driveshaft. Accelerator and brake pedals in the cabin enable the operator to control the speed.
  3. Steering Circuit: The steering circuit is operated by a gear pump that is combined with a special priority valve to ensure easy control of the wheels even when the Deck Lifter engine is in neutral. The steering circuit provides the oil to the double acting cylinder, which is mounted on the front axle.

Safety :

The Deck Lifter is equipped with many safety devices in order to provide a safe work environment for the Deck Lifter operator and others working on the ship.
The main hydraulic safety features are as follows:

  1. If the four telescopic lifting cylinders are not extended by an equal amount, then the system stops immediately.
  2. A safety valve is mounted directly on each telescopic cylinder in order to prevent downward movement that is not initiated by the operator.
  3. Two safety valves are mounted directly on each stabilizer cylinder to ensure they remain lowered while lifting is in progress and that they are not lowered while the Deck Lifter is being driven.
  4. The vehicle cannot be driven unless all of the stabilizer cylinders are fully raised. When the stabilizers are up, a separate proximity switch for each stabilizer monitors its position.
  5. The frame cannot be raised unless all the stabilizers have been completely lowered. Separate pressure switches for each stabilizer monitor this.
  6. The stabilizers cannot be raised unless the frame is fully down.

Additional Safety Devices: 
The Deck Lifter is supplied with many other safety devices, including: