THE HOLLAND TUNNEL OKAY AND UAGEN G05 



Each fun is provided with ji coiiti'ol switch at the motor for 

 emerj^ency or re[)iiir use. Further hx-ul control is provided at the 

 switchboard in each ventihiting buildinjz;, and complete operating 

 control is provided at the main switchboartl in tiic administration 

 buildinjj: where, by a system of si<:nal li{j;hts, it will be possible, at 

 all times, to tell what motors are in operation. 



Air from the intake fans is forced down into the lon<ritudinal 

 duct under the roathvay of the tunnel. From there it is fed through 

 flues 10 to 15 feet apart into a continuous expansion chamber above 

 the curb line at eacii side of the roadway, the flow of air into this 

 chamber being controlled by adjustable slides over the flue openings. 

 The outer side of the expansion chamber is a copper-steel plate 

 which can be adjusted to give an opening of widths varying from 

 34 inches to K^4 inches through which fresh air flows into the 

 tunnel. 



Vitiated air is drawn off through openings through the ceiling 

 into the exhaust ducts. These openings are spaced 10 to 15 feet 

 apart and are from 3 to 6 feet long. They, also, are provided with 

 slides by which the opening can be adjusted to meet the local re- 

 (piirements for air circulation. 



By this arrangement of supply and exhaust ports, fresh air sup- 

 plied to the roadway mixes with the warmer gases and rises to the 

 ceiling where the exhaust ports are located. 



There will be no longitudinal movement of air in the tunnels 

 except that induced by the movement of vehicles, nor will there 

 be any objectionable winds such as would be created by longitudinal 

 ventilation. Tests made with smoke bombs showed that even large 

 quantities of smoke will not spread far from the point of origin, 

 but will rise quickly to the ceiling and be taken out. Similiarly, 

 in case of a fire the hot gasses will rise to the ceiling, where they 

 will be drawn off. There will not be the same danger of spreading 

 t)ie fire from car to car as there would be with longitudinal 

 ventilation. 



As part of the studies for the ventilating equipment, numerous 

 tests in relation to fire were made, both in the test tunnel at Bruce- 

 ton and at the laboratories of manufacturers of fire-fighting equip- 

 ment. These tests included the burning of an automobile drenched 

 with gasoline and with gasoline spilling from a hole in the tank 

 on the car to determine how quickly such a fire could be put out 

 with the hand extinguishers to be placed in the tunnel. 



As a check upon the air conditions in the tunnel, automatic carbon 

 monoxide recording devices are installed in each exhaust duct which 

 will make a continuous analysis of the gases and record it graphically 

 in the control room of the administration building in New York. 

 There, by observing the chart, the operator can increase or decrease 

 the fresh-air supply as traffic conditions change in the tunnel. 



