The contract for this 5¼ mile section was awarded to Dowsett Engineering Construction Ltd and cost £7.6 million of which £1.2 million was for structures. The contract which included the construction of ¾ mile of the M606 motorway and a similar length of the M621 was started in June 1970 and completed in December 1972.

Leaving Hartshead, the motorway passes through the 60 ft. deep Cleckheaton cut to the three level Chain Bar Interchange. This connects with the A58 Halifax-Leeds road, the A638 Bradford-Dewsbury road, as well as having slip roads connecting the M62 with the M606 Bradford South Radial motorway.

On the latter 1¼ miles of motorway between the Chain Bar and Gildersome interchanges the motorway crosses two class A and three unclassified side roads and this length includes some of the largest cuttings and fill areas on the scheme. The total amount of excavation was approximately 5 million cu. yd. of which about 3 million cu. yd. was rock.

This length of motorway runs through the Yorkshire coal fields and special precautions had to be taken to minimise the effect of old workings on the motorway. Eleven abandoned mine shafts were located on the line of the works all of which had to be specially backfilled and capped.

There are seventeen bridges and a major retaining wall. Six of the bridges which carry the motorway are of standard construction, having pre-cast prestressed I-beams, from the Fairclough Factory, with in situ reinforced concrete deck slabs, and reinforced mass concrete abutments with forward sloping front faces.

Four of the multi three or four span bridges over the motorway are of cantilever and suspended span construction. The decks consisting of pre-cast reinforced concrete beams with an in situ concrete deck slab. The decks are supported on reinforced concrete piers and bankseats.

The Chain Bar interchange comprises of five bridges, four of which are of standard construction. The bridge carrying the M606 over the interchange was built to a plan radius of 749 ft. and consists of four simply supported spans of 40, 86, 105 and 43 ft. Structural steel longitudinal plate girders at 6ft. centres act compositely with a 9 in. thick reinforced concrete deck slab, the deck being supported on piers and bank seats.

Agreement was reached between the Ministry of Transport, British Rail and the County Council for certain of the Railway underline bridges to be designed by the West Riding Engineers.

Chain Bar Rail Viaduct carries the railway Bradford to Cleckheaton single track over the motorway, having five simply supported skew (23°) spans. The deck comprises longitudinal mild steel through plate girders, 92½in. deep, with Universal column section high tensile steel cross girders which act compositely with an in situ reinforced concrete deck slab. The deck is supported on reinforced concrete piers and abutments.

Whitehall Road Rail Bridge carries the same line over the diverted line of the A58 trunk road. A similar deck was used with 84 in. deep through girders for a single span of 85 ft.

Unfortunately soon after the opening of the motorway this line was closed. However, both of these bridges now serve as part of the Spen Valley Greenway cycle route.

Hunsworth Lane Bridge has three continuous spans, two side spans of 62 ft. 6in. and a centre span over the motorway of 159 ft. The construction is of twin longitudinal steel box girders with a pre-cast composite reinforced concrete deck slab. The slabs making up the deck being of full highway width of 43 ft. had boxed holes to provide for the shear stud connections.

The longitudinal box beams joined by cross girders are supported by hemispherical bearings on single columns and on bearings at the abutments.

The deck construction was something of a first. The girders were jacked up before laying and jointing the pre-cast deck sections, after obtaining the required strength in the concrete jointing, the deck was lowered onto its bearings at the piers, providing a prestress in the deck slab. This type of bridge was adopted to give required sight lines at the bridge. Although falling under the new Merrison rules during construction, additional stiffening was carried out without delay to the main contract.

It was intended that the two retaining walls should be built to support the westbound motorway slip road embankment adjacent to the works of Hunsworth Dyers Ltd. The walls over 400 ft. long varied in height up to 25 ft. and were of reinforced concrete on bored pile foundations. In the event one toe wall was not constructed.

Above the wall the embankment was to have a sideslope of 1 in 2. However due to the difficult ground conditions found locally during piling, the retaining wall was omitted and the sideslope increased to 1 in 1.4.

In February-March 1977, some 5 years after the motorway was opened to traffic, shallow slips occurred. Failure was almost certainly induced by the inflow of water into the embankment through holes excavated as part of a later tree-planting programme. The holes were dug in autumn 1976 and remained open through the winter acting as traps for surface water.

With wetting of the embankment fill material, the factor of safety against rotation reduced to 0.97.

As the progressive nature of the slips would ultimately threaten the motorway it was considered necessary to obtain a permanent solution. Regrading the side slope to 1 in 2 would ensure the long term stability of the embankment. However the proximity of the dyeworks at the base of the embankment prevented the gradient of the sideslope being reduced without the construction of a retaining wall. Because of the difficult ground conditions a gabion wall appeared to be a reasonable solution."

A tyre wall proposed by West Yorkshire's Engineering Developments Section was found to be £10,000 less than the gabion solution and was submitted to the Department of Transport and approved. The West Yorkshire engineers with their new responsibilities for waste disposal had found another solution to overcome the difficult problem of disposing of worn tyres.

The Chain Bar to Ainley Top section of the M62 was opened on 5^th July 1972 by Mr Keith speed, Parliamentary Under-secretary at the Department of the Environment. The remaining section was opened in the Spring of 1973.