PROTECTION FROM AIR RAIDS

Press, Volume LXXV, Issue 22877, 25 November 1939, Page 11

PROTECTION FROM AIR RAIDS

WORK ON LONDON TDBlg RAILWAYS

- - . - ; OH ERECTED Df%|s TUNNELS. j V - -m ' (nOK OTTB OWX COBBESPOSSBST.) -LONDON, October (L The protection of the London'JE*as», senger .Transport Board’s railWay'and •road service from air- raid damage is costing £1,000,009. The' plain trim volves a vast programme of worhS at, 60 ? underground stations, - 19 :ofS which are closed for teen giant " floodgates will be' built ia® the tunnels of these lines, runnings under the. Thames: In otijex stations® work has to be done to isolate floodins from burst water mains and sewers; S On the Bakerloo line lour floodgates are installed at- Charing Cross anlra two at Waterloo. On the Northrirqj# line two gates have been installed a® Strand and two at TheS line should be open in from six teg eight weeks. Two gates have stOB to be put in at the Bank,’'two London Bridge, and two on the Easw London line. ■ * - B One of the gates at Waterloo Station, at thfe end of the'northbound platform on the Northern line, was seen in action this week. It is of built-up steel, 13in thick, andS weighs nearly six tons. . Thp gates slides horizontally into position with-S in a frame of cast iron across thd| mouth of the tunnel. It can be workedg either- by hand or ,by electricity, ; an<B there are: alternative ; supplies on power. When closed the gate couja|, resist a force of more than 800 torn? which is several times the greatest pressure of water that could briar nap When .an air raid warning reaches - the office’ of the traffic controller- af] Leicester Square Station, the signali “Close the doors? is sent lathe operas.' tors, of whom there ?re alway? twft( on duty at each gate The signal ia| acknowledged electrically from th« operators’ control, cabins.. in wbid|! there -are- illuminated diagrarris shovtei ing whether the under-river secthnaj of line are clear of trains or not. Ihtew locking gear makes it impossible to fiose the gates with, a train between them. Before a gate can be dcsedl the small gaps between the gate-sfR! and the rails are filled with shaped! metal blocks,- lined with rubber,.- so making a continuous runway for the gate'.

All possibilities are allowed for. AS train cannot be caught in a tunnetl Gates can be closed by hand in fourf and a half ■ minutes if the electrt* B current fails. An escape hatch is so placed that normal routine examination of the permanent way can continue if the gates are closed. An ordinary kitchen tap- -looked out of place in the massive structural of the steel gate. It will be used see if the underwater section of tunnel -is flooded. ‘ After the Munich crisis, Londq»; Transport’s engineers made a survey of underground stations. Fifty stag tions were foimd to need measures. At 31 of these, work could' be done .without disturbing At the remaining 19, work was more complex, and stations had to be closed temporarily. ' .-_I At King’s Cross every one of tM* subway entrances to the ticket hall was threatened by th® nearness of sewers and water At one point the floor of a subwaywas only six inches above the roof of one of the largest sewers in Lon*, don. The four passages leading from the circulating area had to be blocked up by the insertion cl bulkheads of concrete up to six feet thick* That Is why, two days before the wars the station had to be closed- ‘