Compressed air illness : an investigation during the construction of the Tyne Tunnel 1948-50 / W.D.M. Paton and D.N. Walder.

  • Paton, William D. M.
Date:
1954
Catalogue details

Licence: In copyright

Credit: Compressed air illness : an investigation during the construction of the Tyne Tunnel 1948-50 / W.D.M. Paton and D.N. Walder. Source: Wellcome Collection.

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    first used in the Howdon shaft on June 2, 1948, and the shaft was completed on July 15. Horizontal tunnelling then began from this side at a pressure varying with tidal and other conditions from 32 to 42 lb. per sq. in. Junction with the Jarrow boring was made on May 14, 1949, the air pressure being maintained by means of a bulkhead previously erected in the Jarrow end of the tunnel. An air-lock was also constructed in this tunnel near the Howdon shaft to regulate the air pressure until caulking was completed. Pressure was gradually lowered and was finally released on January 13, 1950. As soon as the 10 ft. 6 in. tunnel was well started, the boring of the larger 12 ft. 0 in. tunnel for cyclists began in October, 1948. This tunnel proceeded more slowly, and work was held up between March and June, 1949, during which time a shield was erected, on account of the difficult nature of the ground encountered. During the following period,' except towards the end when the small tunnel was being tested for leaks, the pressure was the same in the large as in the small tunnel. On January 12 pressure fell below 15 lb. per sq. in., and the following day the large tunnel borings from the two sides were joined and pressure was finally released. The pedestrians’ tunnel is reached by escalators at either side of the river and for these inclined tunnels were constructed. The escalator tunnel on the Jarrow side was completed without the use of compressed air. At Howdon, work on the escalator tunnel began in April, 1948 and compressed air was used from December 9,1948, onwards, starting at 8 lb. per sq. in.; it was not until March 10, 1949, that pressures exceeding 15 lb. per sq. in. were required. Thereafter the pressure gradually rose as the tunnel was driven deeper, reaching the same pressure as in the horizontal tunnels on June 24, 1949. Work in compressed air, therefore, took place in four phases: 1. Sinking the Howdon shaft. 2. Driving the 10 ft. 6 in. tunnel from the Howdon side, with later locking off and caulking at a lower pressure than the rest of the working. 3. Driving the 12 ft. tunnel starting later than the 10 ft. 6 in. tunnel, but proceeding simultaneously with reduction of pressure during the last few weeks. 4. Sinking the Howdon escalator tunnel. POPULATION AT RISK AND WORKING SHIFTS Altogether a total of 376 individuals were exposed to compressed air during the construction of the tunnels. This population can be divided into two main groups, those working in shifts (177), and those entering and leaving the tunnels to perform tasks, the duration of which did not coincide with that of the regular .shifts (199). The shift workers varied in number according to the number of working faces, the amount of caulking being carried out, etc. But, as a rule, There were at each face: j 1 leading miner, 2 miners, 3 labourers, 1 caulker, I 1 runner. I The shift duration (i.e. the time spent at the working face and excluding liiecompression time) was 6 hours until October 3, 1948, when it was lengthened jio 8 hours. During a period of difficult working on the 12 ft. face (from March l»o June, 1949), the shift duration was temporarily shortened to 4 hours.