Canning Conveyor supply conveyors for Heathrow Terminal Five project
Canning Conveyor has supplied feed extraction conveyors to main contractor Dosco Engineering for a project at Heathrow Terminal Five.
Dosco has over 50 years experience in the design, manufacture and refurbishment of machines and systems and has recently been awarded the contract to design and supply a SB400 Boom in Shield Tunnelling Machine to drive the Baggage Tunnel for BAA’s new Terminal Five at Heathrow Airport, London.
The tunnels pass through an ideal tunnelling media - London clay. Dosco road-header booms have in the past been used in this type of ground, with great success, to excavate the Piccadilly Line Extension, Heathrow Terminal 4 and 5 and projects for London Transport, Jubilee line including the Heathrow Express Link project to Terminals 4 and 5.
Canning Conveyor supplied two 800 mm wide conveyors for the project with a capacity of approximately 600 tph, based on a specific gravity of 1.68 tonne/m3
The first conveyor which accepts material feed from the tunnelling machine into a loading hopper is 21.5 metres in length, with the first 7.5 metres inclined and the remainder horizontal.
Manufactured with channel frame construction this conveyor is powered by a 30kW shaft mounted geared drive unit driving a 500mm diameter x 900mm face drum with full rubber lagging, providing a belt speed of 2.5 m/sec.
3-roll fixed troughed idler sets at 600mm pitch support the belt with standard flat-faced return rollers, with 102mm diameter rubber coated close-pitched idlers sets in the loading section.
Canning Conveyor also supplied a cross feed conveyor fitted with a loading hopper. This conveyor is 2.7 metres in length, of similar specification and is powered by a 11 kW shaft mounted geared drive unit driving a 315mm diameter x 900mm face drum with full rubber lagging, providing a belt speed of 2.5 m/sec.
3-roll fixed troughed idler sets support the belt with standard flat-faced return rollers again with102mm diameter rubber coated close-pitched idlers sets in the loading section.
Belt tension on this conveyor is achieved by a manually operated hand pump operating two hydraulic cylinders; this arrangement is part of the tail drum mounting assembly.
The specification was completed by the inclusion of a torsion type belt scraper fitted adjacent to the head drum, and a plough to both conveyors.
The shield which is of segmental construction is 5510mm outside diameter and incorporates 18 push cylinders and 2 face support cylinders. The cutter boom is a 142 kW (190 hp) single speed boom, having a clay head, to excavate the ground.
The boom is fitted with a flipper plate to assist with loading. This flipper plate is hydraulically operated, folding flush with the boom when not in use. The TBM back-up consists of 8 sledges which run on wheels on the inside of the built lining.
These sledges carry the hydraulic power pack, electrical control panel and transformer, ventilation tubing handling system and all the other requirements of a 21st century tunnelling machine.
Commenting on the conveyor installation, John Crompton of Dosco said, "Canning were very helpful with the specification of the equipment supplied."
The 2.1km tunnel is being built by Ferrovial Agroman Airports (UK) Ltd; part of the world renown Ferrovial Agroman construction company. Commenting on the project, Tunnel Manager Alfonso Chicharro said, "We have high hopes for this and other ventures in and around the UK".