Mk.2 Talus MB-4H


The Talus MB-4H tractor was designed in the early 1990’s and was required to haul the A75 lifeboat and carriage, weighing approximately 3 tonnes.  In 2005 the A85 carriage and boat were gradually introduced into service, followed by an A85 Angled carriage that has a laden weight of 6.5 tonnes. Not surprisingly the tractor started to struggle with the increased payload, and a Mk2 version was designed using the following requirements and constraints:

  • Output 50% more torque
  • Maximum speed unchanged
  • No change to the engine
  • Joystick steering in addition to the existing twin hydrostatic steering wheels
  • No significant change to the vehicle structure.

To achieve this requirement the following changes were instigated:

  • The drive system was completely re-worked with fixed axles being replaced with wheel motors, and a fluid diff lock valve was replaced with the Poclain “Twin-Lock” system.
  • The engine speed control was previously by Bowden cable and is now “fly-by-wire”.  The mechanical control system on the existing diesel engine is operated by an electrical actuator.
  • The operator instrumentation and controls have been completely revised to provide a more ergonomic solution.
  • An HMI has been incorporated to provide a detailed level of on-board diagnostics.

In conditions where traction is poor the Mk2 machine has far superior performance to the original tractor, as the maximum torque can be developed at a much lower speed.


Clayton Engineering are members of the following organisations: Member - British Safety Council TWI - World Centre for Materials Joining Technology LEEA - Lifting Equipment Engineers Association ISO9001