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21730-Wicket Girders and Machinery of Emergency Dam, Gatun, Panama Canal.
The wicket girders of the emergency dam, 'vessel fails to stop before entering the lock,
described in views 21726, 21727, 21728, can the chain will be stretched from wall to
be seen here to great advantage. At the wall. W-hen the vessel comes in contact
rear end are seen the gates to be run down with it, the chain will be let out automat-
along the girders when the latter are p't ically at its ends, exerting a resistance in-
in a vertical position along the width of the ci casing as its length increases. A ten thou-
canal. and-ton vessel running four miles per hour
It is estimated that, in case of damage to can be I opped within 73 feet. In case the
the gates by the ramming of a ship, the chain breaks and fails to stop the vessel
water would flow with a velocity of j2 f-ct and the vessel rams the first gate, a second
per second and a discharge of O0,000 cubic gate will be put in operation. If the vessel
feet per second, constituting a force suffi- breaks thru the chain and the two gates,
cient to tear up the floor of the lock. To the emergency dam can then be used to
prevent ramming of the gates by a vessel, check the flow of water until repairs a. r
a second protective device has been in- made.
stalled, the protective chain.T In cae the
.Copyright 19g3, by The Keystone View Company.