Fully-Inflated Life Raft Deployed by Sealed Belt Drive
Thanks to the expertise of Ayrshire-based Emergency One, the Nottinghamshire Fire and Rescue Service now operates a purpose-designed and award-winning specialist rescue unit (SRU) that is unique. What makes this vehicle design so special is its stowage of a vast range of dedicated equipment including a fully-inflated boat for water rescue, positioned on a trailer for quick off-load.
Emergency One did consider proprietary systems for deploying this heavy equipment but found none to be suitable. They all presented problems for Emergency One’s engineers as their design, powered by large pistons, would not allow the inflated trailer-mounted boat to be fully enclosed within the roofed body of the SRU.
So, as the weight of the towed boat dictated it had to be deployed via an automatic system and not manually handled, Emergency One set about designing its own compact version to fit into the roof void. And central to this Automatic Boat Gantry System (ABGS) is a HepcoMotion® Sealed Belt Drive (SBD).
Emergency One is one of the UK’s leading manufacturers of fire and rescue vehicles both for the home market and for export, through the MoD, to countries such as Cyprus and the Falkland Islands. All vehicles are built to individual customer specification. Variations range from water, foam and equipment carriers and small quick response vehicles to standard pumping appliances and off road animal/water rescue vehicles.
The company is therefore highly experienced in adapting its designs to suit different requirements and developing new and bespoke features. “Indeed this SRU was one of the largest vehicles we have ever built,” explained Emergency One’s Lee Dawson.
He continued: “A very important factor in its design is the boat’s stowage in a sealed compartment to minimise its exposure to the sun and other elements to prolong its service life. It also had to be fully-inflated and instantly ready for use to cut the Water Rescue Team’s response time and mounted on a trailer for off-road incidents at a loch or reservoir for example.”
The company assessed a number of linear products for its ABGS including screw drives but the overriding benefits of the HepcoMotion® SBD were its robust construction, load capacity and availability in any length of travel. Naturally the system needed to be corrosion resistant, a standard choice within the HepcoMotion® product programme.
“The deployment of the boat required a certain amount of travel to allow the Water Rescue Team to safely mount and dismount the boat at the rear of the vehicle and the SBD also gave us this essential quality,” Lee Dawson added.
HepcoMotion® developed the SBD to provide an exceptionally reliable product for high loads and demanding cycles. It features a unique and superior sealing method that excludes debris and is available in beam lengths of up to 6m as standard.
In the resultant ABGS design, the SBD is mounted to the floor of the compartment, connected to a tilting beam on which the boat and trailer are stowed. A pivot bar, with stops, arrests the beam at the required height and angle; the mechanism is activated via push buttons on the side of the SRI. When the ‘out’ button is pressed, the SBD begins its travel towards the rear of the vehicle, pushing the tilting beam, boat and trailer out of the back of the body.
This movement continues along the full length of the SBD until the boat is fully tilted. After use, the boat and trailer are pulled back onto the vehicle by the SBD to their fully stowed position where automatic air pistons lock the system in place.
This mechanism is driven by a pneumatic rotary motor that is connected to the end of the SBD and for which HepcoMotion® provided a dedicated mating face. The overall load that the SBD pulls is around 250kg. However, due to torque at the point where the boat stalls in its fully lowered position, the motor had to be over specified and regulated to lower the speed of travel to around 3m per second.
“One of main challenges of this project was indeed determining the tilt and stress points to verify whether the design was viable,” Lee Dawson continued. “We also needed to write special computer logic to regulate the air system to ensure smooth and safe deployment.”
The SRU was delivered to the Nottinghamshire Fire and Rescue Service during the summer. Chief Fire Officer Frank Swan said, “We are incredibly proud to have been instrumental in producing such an impressive and operationally effective vehicle which will further enhance our specialist rescue capabilities. To be able to transport this amount of equipment, access and deploy it safely and utilise it for a range of protracted incidents, is a great achievement.”
The vehicles storage space and equipment deployment mechanisms are undoubtedly the star qualities of the SRU. Lee Dawson concludes: “The design has attracted great interest. Earlier this year we exhibited it at the Scottish Fire Exhibition where it was judged to be the ‘Best Vehicle in Show.”< BACK HEP\457