Evening star., 1927-12-04
NEW YORK VEHICULAR TUNNELS
TEACH VALUED TRAFFIC LESSONS
First Week of Operation More Than
Justihes Claims and Expectations.
Increased Utility Is Predicted.

s a.m.-930 a.m.-Motorist commut
ers Uhe Oranges. Montclair, etc.) test
ing the tunnel as a substitute Tor ran
way travel
$50 0-Noon-Trucks.
Noon.3 p.m.-Trucks and pleasure
cars, about even.
pm.-6 p.m.-Heavy passenger
traffic.
7p.m.-s p.m.-New York bound the
ater crowds from New Jersey.
..11p.m.-Sightseeln ana tour
lists.
II p.m..1 a.m.-Theater crowds re.
turning to New Jersey.
On the opening day the travel was
almost entirely pleasure cars. The
host of 5l.74S vehicles paid gross tolls
of S25,S7S20 for the day. Congestion
at the tunnel mouths caused delays
which inspired misgiVing. The exit
piazas. on the other hand, were kept
we'll cleared. But at the entrance plaza
the tunnel lines waited as many rs 10.
II and even 16 abreast. Yet only two
cars abreast could enter the tube at
once This meant that the broad for
nation had to be correspondlngly
squeezed" to get under way. In New
Jersey on some approach streets the
waiting lines were backed up for
miles.
The spectacle seemed to indicate
that under heavy pressure the tunnel
had revealed serious limitation
Official comment was to the effect
that this but emphasized limitation
inherent in the present traffic situa-
ton as whole. The point was made
that n two-lane tube--the size of each
Holland tube--could be wholly efficient
only within radius reasonably
commensurate with its own capacity.
In other words. a two-lane tunnel
primarily could service" only what
could be called it's own 'neighbor.
hood"
"Neighborhood" Tunnels.
Those seeking to give traffic relief
had accordingly to think in terms OF
"neighborhoods," and not of a city.
or State, as whole. The only solu-
ton, it was urged. was to provide a
series of sufficient additional neigh
borhood" tunnels. The Holland Tun'
mel was stoutly defended as being
fully equal to all that could be ex-
pected of it. One important extra
neous service it might render, accord
ing to critics, was to call attention
to the need of not only more tunnels
but of their conception and co-ordi-
nation in an intelligent city planning.
The $48. 900 spent on the Hol-
land Tunnel has bought not only the
longest vehicular tunnel in the world
but a presumptive insurance or New
York City against the danger OF a
food blockade as result of Winter ice
jams ih the Hudson River.
OF the problems involved In the
building of the tunnel. the most seri-
Gus was that relating to ventilation.
The engineers believe that the sys-
tenn developed in the Holland tubes
will stand az the model for builders
Of other vchicular tunnels.
The problem of providing fresh air
and removing gas-poisoned air from
conduit $3.50 feet long actually re-
suited in the working out of almost
an entirely new ventilating science.
Each tube is gale -jacketed" above
| and below. A pumping chamber ~
ing between the roadway floor and the
circular outer shell of the tube and
an exhaust chamber occupying the
space between the ceiling and the top
of the shell contain roaring air
streams swept along at a speed of
72 miles an hour.
Air Circulation System.
The good air enters the tunnels
from vents near the floor and Is suck.
eU uDW1TO lHTOuSH the SAfidUSL VeHtS
overhead. The circulation of the air
is conspicuously upward. There is no
sensation of a wind or breeze blow
ing" longitudinally.
Eighty-four powerful blower fans
installed in land buildings on shore
change the air in the tunnels AZ times
an hour-about once every minute anC
a half. Even at the last Sundays
peak only Sc of these fans were neces
sary, and since then even a fewer
number have been required.
The tunnel engineers determined
after exhaustive experiments that 4
parts of carbon monoxide gas in every
| 10000 are as much as can be safely
| breathed. The ventilation system ir
| the tunnel is scaled to maintain this
safety factor. AS matter of fact
| the engineers say that the ventilatine
equipment has proved far more eff
cient than necessary. Opening day
tests showed that, at the worst, there
were never more than 1.8 parts Of car
bon monoxide gas in every 10, 900 parts
of air. and that the prevailing average
was even less. The weekday average
so far has been around one half Of one
| part.
The surprising thing about the all
| in the Holland Tunnel is that it is
| actually clearer and more pleasant tC
breathe than the air outside, especially
the air along the smoke-draped water
| front of Jersey City, where the tunnels
| end.
The fact that certain sections of the
| tubes rise and fall with the river tides
| is not generally known. Part of the