The Shannon launch and recovery system has been developed to launch and recover the 18-tonne lifeboat from extremely rugged and harsh environments. The tractor and carriage can negotiate beaches with steep gradients and gullies, or travel long distances over flat, saturated sand or shingle.
Connected by a pivoting swan neck, hydraulic motors power both the tractor and the rear carriage. The system incorporates several unique and innovative features including a software-controlled four-track drive system that provides exceptional mobility.
The vehicle can be operated in calm water up to a depth of 2.4m, and shut down to withstand full submersion in water up to 9m deep if stranded on an incoming tide.
The Shannon-class all-weather lifeboat can be launched and recovered bow first. The cradle that carries the lifeboat rotates through 180º using a unique turntable feature built into, the carriage. This reduces the time and space needed to prepare for relaunch – a crucial factor if the Shannon is to receive more than one callout in a day.
Width 3.5m; Height 4m; weight 37 Tonnes; Winch pull 18.5 Tonnes; Engine Scania DC13 12.7 litre turbo-charged diesel, 331kW. Fuel 300l; Max speed 10mph.
Cab – The cab is built from composite materials and provides good visibility and driver protection. The door and hatch have watertight seals in case of immersion. Access to the cab and the surrounding walkway is provided by means of a ladder on the front of the tractor. There is space for the driver and 2 others. The driver can face forwards or backwards on a 180° swivel seat.
Controls – The controls and displays needed to operate and monitor the equipment are located in the cab. Some, like the joysticks, are sited on the driver’s seat arms to make the unit easier to drive. CCTV is provided to ensure some winching operations are conducted safely.
Running gear – The carriage and tractor have identical hydraulically-driven track systems with low maintenance rubber tracks and road wheels. The tracks pivot to allow them to paddle over undulating or uneven ground.
Winch – The winch is used to recover the lifeboat onto the cradle and can also be used for self-recovery of the unit. The winch rope is synthetic instead of the usual wire type. It is light and strong and will not whip or recoil if it were to break or snatch, making it safer for the shore crew.
Swan Neck – The swan neck connects the carriage to the tractor. This feature can angle the carriage for slipway launch and recovery. It is also used to reduce the overall height of the unit when entering or leaving the boathouse. The carriage swivels on a 5th-wheel as a normal articulated vehicle.
Carriage Foot – The carriage foot is used for emergency disconnection if there is a problem with the unit and is not normally used during launch and recovery. This is the silver curved piece at the foot of the swan neck.
Carriage unit – This allows the lifeboat to be launched and recovered bow first. The unit has a cradle to support the lifeboat. The rig can be tilted for launch and recovery by means of hydraulic rams on the swan neck and drawbar assembly. When on the carriage, the bow of the lifeboat extends 1m over the front of the cradle.
Cradle – Righting wheels lift the lifeboat from a heeled state (lying partially on it’s side), and protect the hull during recovery. Ratchet straps hold the boat as it is rotated. The bow strop is tightened so the wedges on the stern of the boat locate on the swan neck. The boat is now ready.