New-York tribune., 1897-07-11

he flrst recalls the construction of the old grip
and the defect in it which has now been RENE
died The hanger which reached down into
the cable conduit from each car, carried at its
lowest extremity tWo horizontal metal blocks.
one above the other, and little way apart. The
cable passed between them. When the gripmaa
scrs we'd the proper wheel out on the dashboard
In the right direction the two blocks Tor jaws
were made 10 approach each other When the
grip was firmly applied there was pressure OF
three hundred pounds to the square inch be-
tween the Jaws. This gave the device such a
hold on the cable that the car had to go along at
tho same rate as the cable did, which was eight
or ten miles an hOlr.
IT, however, the street was crowded or there
were slow teams the track just ahead the
gripman not only applied his brake lightly. but
relaxed the pressure on his grip to quarter or
a half of that required for full speed. This
procedure would enable the cable to slip some
what and yet there would be enough friction be-
tween 1t and the jaws TO do little pulling. Ac-
cordingly the car would be kept moving at re-
duced speed.
When a car got on curve, however, new
difficulty arose. The adjacent surfaces OF the
two Jaws, upper and under, were only signify
grkoved and there nothing to keep the
cable from slipping out sideways between them
If it wanted to. SO long as the car was ON
straight piece Of track the cable showed no dis
position TO do So 1t then kept in the same YER
ticpl plane as the grip. But on curve, even a
slikht curve the cable was under s>rain when
tekded TO pull it out on one side from between
the Jaws. NJw SO long as these were jammed
down tight they would hold the rope so teha-
cfously that escape impossible. But if the
pripran lessened the pressure TO anything like
tina call le
one side. two or three or four inches clear Of the
Yrip Then no matter how vigorously he screwed
down the jaws, there was nothing for them to
take hold Of. He had lost his connection with
the motive power Of the road and the car was as
nelpless as a steamship with broken crank.
IIence ON a curve il was imperative that the
giip be kept at full pressure.
The great problem, then, TO devise way
by which the cable could be prevented from be-
having in this way on curves, whenever the
pressure was relaxed. Chief Engineer Pearson
of the Metropolitan Traction Company says
that several men in his department have had
the matter under consideration for at least thiee
years. And though in the mean tlnle there mas
been some modification of the plan originally
suggested the essential principle OF IL mas sceh
retained In the attachment which was hnally
made
Directly in front Of and behind the upper jaw
OF the old grip a small block Of Harveyizcd steel
has been put in position. The two really consti-
tute slight extensions Of the upper jaw. But, as
will be in referring 10 the annexed draw
ing the main jaw is open At the side, so that You
can see the wire rope underneath very plainly.
But the extensions inclose the cable completely,
so that il cannot slip out sideways under any
circumstances 1t should be explained, in pass
ing that as provision against accident the
company has two cables in the conduit. although
only one is in service at time. They are few
inches apart 1t is therefore desirable 10 nave
the main part Of the gripping apparatus wide
enough so that it will take hold Of either Of
these cables occasion may require. For the
same reason the little attachment which has
noE been made TO the upper jaw has two fore
anA-aft tunnels running through ii, one for each
cak4e
WHEN A CURVE is REACHED.
When car this equipped comes to a curve
now, the cable is pulled well to one side but it
cannot possibly escape. 1t may rub the edges OF
the inclosng addition. and wear ii if free slip
lengthwise. But that is ALL To provide for this
contingency the attachment Is made Of steel
which has been hardened by the same process
that Is employed with modern armOr plate. The
utmost possible durability has been sought. New
part VIII be necessary The wire rope. too, will
suffer from this abrasion
Chief Engineer Pearson roughly estimates the
increased cost to the company per year
cables alone as a result of the change at some
thing like $25,UBJ, and the renewal OF the at
tachIuents may increase the annual expense
SO 600 or $1,000 more The latter. however. is
too liberal an estimate possibly. The actual ex
pense OF making the change has been about $50
per car A complete grip costs nearly or quite