M62 in West Yorkshire

INTRODUCTION

At the outset of the investigation it was considered that the minimum survey information necessary to locate the motorway successfully would be up-to-date 25 in to 1mile plans, with contours at 5 ft intervals, as suitable Ordnance maps were not available it was decided that the quickest accurate method would be to undertake this work by an aerial survey. With Ministry of Transport approval this work was put in hand in December 1961.

In order to limit the areas for full aerial survey a model to a scale of 6in to 1mile, with 2 to 1 vertical exaggeration was constructed from the available Ordnance Survey detail. This enabled an appreciation to be readily made of the routes, which were to be investigated more fully.

As the choice of lines was narrowed down by design criteria and other considerations, planning restrictions previously imposed on building development were lifted on the routes which had been eliminated, and the 'zones' of restrictions reduced to the minimum necessary.

More detailed information was required on present and future traffic patterns and in June 1960 an origin and destination survey, with 27 survey points forming a number of screen lines, was carried out.

From this survey and more localised surveys from the County Boroughs of Huddersfield, Bradford, Halifax and Leeds the traffic needs of the West Riding conurbation were assessed.

Considerable problems were presented in the routing and design of the Pennine Section of the motorway by features of geology, geography and climate.

The weather in the Pennines provides hazardous conditions for the motorist with ice and snow in the winter. Fog, poor visibility, torrential rain and gales are also common throughout the year. It was obviously of great importance to minimise the effect of these hazards by careful selection of the route. A network of ten weather stations was set up in January 1962 along the alternative 'high' and 'low' level routes to provide comparative recordings of temperature, visibility and snowfall. From the data obtained it was estimated that the higher route would have 30 to 40 percent more fog; a 10 percent greater frequency of frost and 20 percent more significant snow. For these reasons the low level route was adopted.

This route crossed the county boundary at Windy Hill at a level of 1220 feet, quickly falling to 850 feet before crossing the Dean Head Valley to join a common route at Pole Moor. Through the Heavy Woollen Area between Brighouse and Morley a northern route was chosen of the two investigated.

Through the mining area between Lofthouse and the Great North Road the route to Selby Fork was found not to be practical and that to Ferrybridge was selected.

The problems of crossing the Pennines were unique and further specialised studies were undertaken after consultation with the Ministry and the Road Research Laboratory.

  • The construction of two trial embankments close to the line of the motorway at Moselden Height to study the effects of wind and snow on an exposed section of the motorway.
  • Field trials using various types of fencing on the Pennines to ascertain the extent to which they cause snow drifts and their efficiency as barrier fencing against sheep.
  • Wind tunnel experiments to observe the airflow in major cuttings and over high embankments.
  • Field trials to ascertain the best way of growing grass, trees and other plant life on the moors of the Pennines, which are subject to a high degree of air pollution.
  • Blasting and compaction trials to find the best methods of dealing with the large quantities of rock involved (some seven million cubic yards) over the whole length of the motorway.

Investigations were also made into the existing use of land which showed the overall location of mining, other industry, and agriculture. Consultations with the County Mining Engineer gave information on subsidence in the area of motorway and on the general geology. This was further supplemented by a preliminary soil survey with trial boreholes along the alternative lines of the motorway.

The Pennine crossing posed major structural engineering problems and special studies were made into tunnels and ventilation, two level structures, canopies and road heating.

Construction of two trial embankments was undertaken in the autumn of 1962 using low cost materials, fly-ash, shale and a skimming of fine cold asphalt as a surfacing. Each embankment, of ranging heights and side slopes, was 100 yards long and to full motorway width.

A full time observer took daily measurements of snow depths and to record drift patterns. Continuous recordings were made at the site of temperature and wind speed and direction.

The results of these trials showed that side slope was more critical than height and that a slope of 1 in 5 was found to be the critical slope where snow was swept away. When roads in the locality were experiencing drifts of 8-12 feet the trial embankments were generally blown clear.

Two very deep cuttings at Windy Hill and Dean Head up to 150 feet deep required careful consideration and arrangements were made with the National Physical Laboratory to undertake wind tunnel tests.

The simple conclusion drawn was that in deep cuttings, space was the key factor. As a consequence the width of formation was increased for storage of prolonged snow, and to avoid avalanche conditions, side slopes no steeper than 1 in 1, with berms for increased storage were adopted. It was also found that at cut fill lines snow fences should be erected.

Coincidentally, Huddersfield Water Undertaking had been seeking to build a dam in this locality for some time, to supplement the Booth Wood reservoir. It was suggested that consideration should be given to using a high motorway embankment as an impounding dam. Huddersfield had engaged A.H. Waters and Partners as Consultants, with Professor Nash as geology specialist, and some fascinating technical meetings took place.

At this early stage both authorities saw the advantages of a joint scheme and a sound working partnership was founded.

In a co-operative exercise that is unique to this country, and possibly in the world, many legal, political and administrative, as well as engineering problems had to be overcome.

Having reached an initial agreement on a combined dam and motorway embankment each authority then progressed with its own planning - the Corporation with detailed design of a comprehensive water supply scheme, including tunnels, treatment works, pumping stations, catchwaters and aqueducts; and the County Council with the motorway. For design and supervision of the dam the Corporation appointed Rofe, Kennard and Lapworth as their consulting engineers.

This was the first time that a dam has been designed to carry a motorway on its crest and inevitably a number of novel problems had to be solved. On the legal side, Huddersfield Corporation had to promote a private Bill in Parliament to obtain the necessary powers for the work, which were eventually granted in the Huddersfield Corporation Act 1965. No less a problem was the sharing of costs between the water and motorway authorities. Then because safety was paramount the Minister appointed the Corporation as his agents for the section of motorway across the dam together with full and complete responsibility for all aspects of the structure. In addition, it was necessary to acquire several farms.

At this stage the basic design had proceeded to the stage where centreline levels had been established to achieve an approximate balance in mass haul quantities. It had been calculated that about seven million cubic yards of rock - mainly Kinderscout Grit - would need to be excavated over the length, the most spectacular section of earthworks being at Dean Head and Scammonden where the road would need to pass from cutting about 150 feet deep to cross a steep-sided valley on embankment 200 feet high or thereabouts. The main difficulty to be overcome was that while highway engineers were seeking a stable embankment in which adequate compaction to avoid settlement was combined with free-draining characteristics, the Water Authority's target was a water-tight (earth) structure incorporating clay core, sealed foundations, armoured (rip-rap) face, and so on.

Added to this conundrum there was the whole question of how to excavate 7 million cu. yds. of rock and place it in embankment in a reasonable time at a reasonable cost. There were many characteristics of the Kinderscout and other local gritstones with which the engineers were not familiar within this context and they would be literally breaking new ground. It became clear that fairly large scale field trials needed to be undertaken, in which the Water Authority and their Consultants would be invited to participate. A site at Dean Head was chosen (where some preliminary snow accumulation measurements had already been undertaken), and a contract let to John Laing, primarily on a Dayworks Basis, in the sum of £150,000.

Site offices were set up at Dean Head that Spring of 1964 and the whole of the summer months devoted to the tasks of establishing:-

  • The optimum blasting pattern to produce rock capable of being placed in, say, a 3ft. layer depth, and having graded particles to produce satisfactory interlocking, filling of interstices and mechanical stability. (Sieve analysis of 2-ton samples in this context proved somewhat tedious!)
  • The plant required to give satisfactory consolidation.
  • The most practicable compaction specification, whether by method or end result.
  • The weathering characteristics, porosity, and frost susceptibility.
  • Embankment side slopes and long term stability of cut faces.
  • Acceptable working tolerances for formation levels and sides slopes in cutting.
  • The timescale likely to be involved, having regard to overall programming requirements.
  • Anything else relevant to the overall requirements, including separate studies initiated by Prof. Nash in relation to specification for the Dam, and the forming of section of shallow embankment of varying side slopes to enable snow accumulation to be compared in the coming winter.

I.C.I. Explosives Division gave advice on drilling pattern and depth, amount of explosive per hole and stemming details. They were told the overall objective and they provided a recipe for the Contractor, who duly complied.

The result was far from satisfactory, producing large gritstone lumps - which were simply not suitable for a motorway embankment. The West Riding engineers decided to proceed on their own. They persevered in our search for the optimum combination, attracting the interest of civil engineers from far and wide with their pioneering efforts.

By July they had sufficient information to be able to advise the design team of the practical time scale for incorporation of the earthworks element in the overall programme for the whole 39 miles of the M62 under design, which they were anxious to complete and present to the County Council and to the Ministry of Transport. It was decided that the earthworks from the Lancashire boundary to Pole Moor (6 miles) could be realistically undertaken from April 1966 to September 1968, primarily in the two summers of 1966 and 1967, given reasonable weather. This would lead to an overall target completion date of June 1970, and a detailed programme for the various sections of the motorway was formulated on this basis.

The trials continued, both to fine tune the blasting and excavation details and to produce a method specification, which it was now quite evident would be more practicable than any required density end product specification. Various types and combinations of compaction equipment were tried on different layer depths, the assessment of results by digging trial pits, with attendant sampling and density testing being particularly tedious. Further sampling and laboratory testing were also undertaken to meet Professor Nash's strict control requirements for dam construction.

Much effort was put into harmonising the objectives in this respect, till the fairly obvious compromise was reached, the design of the dam would incorporate a thick layer of the clay to act as a seal on the upstream side, brought up with the embankment as tipping proceeded, the face to have rip-rap protection, the base to include a curtain wall and the sides benched in with additional clay sealing.

The rock trials were not the only experimental work undertaken on the top of the Pennines that summer. One of the things we needed to know for fence design was just how high your average hill sheep could jump, since the prospect of mobile mutton meandering across the Motorway was not a happy one. Estimates varied, even from experienced hill farmers. Finally, one of their number offered to help us mount a practical test. He had some ewes in season which he put into a sheep pen, accessible by barrier of adjustable height, his prize ram on the outside. This noble animal finally cleared 5'6" in his eagerness to get to his harem. Very reluctant he was too, once having entered the sheep pen, to be forced to return outside to have another go as we gradually raised the barrier. Allowing for appropriate exhaustion factor, we concluded the design height for the motorway fence across the moors should be six feet. An environmentally-friendly type of fence to this height strung between slender pylons was duly selected.

Following the detailed investigations on the route, the draft section 11 Scheme for the length between the County Boundary and Outlane was published in October 1963 and the scheme made in October 1964 with the proviso that the Minister would consider objections between Pole Moor and Outlane when the draft scheme for the next length was considered.

The next length between Outlane and Lofthouse was published in February 1964. Objections were received and a Public Inquiry was held in County Hall on 25-27th May 1965, Sir Fredrick Armer KBE CB MC was the appointed Inspector.

Alternative lines put forward were investigated in detail and proved to be either more technically difficult or more costly.

Following a site visit and meeting with objectors the Inspector submitted his report and on the 3rd August 1965 the Minister made the scheme on the draft line. Some 18 months having lapsed between publication and making the scheme.

The draft Section 11 scheme between Sheffield - Leeds Motorway M1 at Lofthouse and the A1 at Ferrybridge has published in October 1965. Draft side road orders followed.

In time all tasks were completed, contracts prepared and tenders could be invited.

Eleven major contracts were required to take the M62 Motorway from Lancashire County boundary, in the West, to Ferrybridge Interchange on the A1 London-Edinburgh Trunk Road and then extend eastwards to Goole and subsequently to Hull.

Two lengths of Motorway connect the M62 to the major cities of Leeds and Bradford, the M621 and M606.

From the initial invitation to the West Riding County Council in January 1962 it was to take until May 1976 to complete the M62 and involved the North Eastern Road Construction Unit, the Sub-Units of the West Riding and Durham County Councils, and the consulting engineers, Scott Wilson Kirkpatrick & Partners.

The sketch plan below shows the sections described in the summaries of the M62, related to their current junction numbers. You may click on any section to bring up the appropriate page.

Lancashire - Yorkshire Motorway M62