The sun., 1908-04-05
MAKING BRICK UNDER WATER
ONE PROBLEM THAT CONFRONTED
HUDSON TUNNEL BUILDERS
SsI'od BY Hardening WITH BlOwpips Flames
the Clay Dumped In 10 Stop = Leak
Canvas Cover sunk From the Surface

the Clay Dumped In 10 Stop . Leak
Canvas Cover Sunk From the Surface
Of the River Met Another EMERGENCY
'one or two Of the most interesting in
cidents In connection with tho building OF
the two Hudson tunnels just opened for
trafic have escaped newspaper notice up
TO this time, for the reason, / suppose, that
the men who put through great engineering
works are not given TO boasting,' said an
official OF the Hudson and Manhattan Rail
road which operates the tunnels.
"One Of these was the occasion which re-
suited In making brick for the first time on
the bed Of a river, and the other was the
occurrence under the Lackawanna coal
docks in Hoboken
The north tube, as is we'll known, is an
extension Of the old tunnel started years
ago. which came to a halt 100 feet away
from reef Of rock standing from one to
sixteen feet above the intended grade Of
the tunnel When our tunnelers took up
the work they found that before the shield
arrived at this point they would have to
build a temporary workshop in the river
ahead Of It so as TO build on the shield a
steel apron under which the men could
work while blasting and drilling the rock
out Of the way Of the shield. The bed Of
the river above the rock was soft sand and
above that was about s1ty-hve feet Of
water.
Blasting the rock with 80 slight cover
and with such heavy water pressure above.
1t was feared. might result In the heading
being blown out. For that reason barge
loads of clay were kept constantly near
that point to be dumped in. The expected
blowout occurred after few weeks and the
900 feet already tunnelled between the
lock and the heading was flooded. The
men all got out safely, and by getting the
bargeloads OF clay into action quickly the
hole was filed. The water was pumped
out and within eleven hours the men we're
able 10 return to the heading on raft. |
No great damage was done and work was
resumed after only twenty-one hours had |
been lost.
1.-TWO other similar blowout occurred |
" lille the tunnel was being pushed across
the 100 feet Of reef, all Of which led up to |
the interesting circumstance Of submarine !
brick making. Al the extreme eastern eud
Of the reef the rock rose about sixteen feet
above the bottom Of the cutting edge Of
the shield. The tunnel at this point Is so
near the bottom Of the river that the clay
v a. almost fluid and continually slipped
INTO the pockets Of the shield 80 that the
men could not get underneath the apron
70 drill the rock Scow after scow was
Jumped, but the clay still leaked.
As q last resort blowpipe flames fed by
vo tanks OF kerosene, were directed against
he exposed clay until it was thoroughly
hardened, 20 as TO hold its position while
he men drilled the rock. The blowpipe
process took eight hours, during which
ime streams Of water we're played on the
held structure continually to prevent II
,elng damaged by the high pressure. The
operations were successful here
'ecause Of the protection from the sub
marine brick.
The south tube furnished the other in
ident have mentioned At the beginning
I the work there the shield on the Hoboken
ide as being driven through silt with the
held doors closed 10 save the cost Of
Xcavating While the heading was under
he Lackawanna coal docks the superin-
endsnt thinking that the shield W as moving