The Jersey City news. (Jersey City [N.J.]) 1889-1906, 1889-07-03
CLEVER ENGINEERING.
How the Iron Trest1e Took
the Place Of the Wooden
One at Harsimus
Cove.
TRAFFIC WAS LITTLE DELAYED.
When All Was Ready the New
Trestle Slid Into Place Like
Magic.

People who ride up and down the Newark
avenue hill must have noticed the trans
formation that the Harsimus Cove trestle,
of the Pennsylvania Railroad, has under
gone within the last two months. For
years an unsightly wooden trestle sup
ported by heavy beams which shut out
the view beyond them has disfigured the
landscape-such as it it-of the meadows.
Today handsome iron structure stands
in its place.
The noticeable point is that the one has
been replaced by the other without any
interruption of the traffic that ordinarily
passes over it. Chief Engineer Brooks
this morning described the manner in
which this engineering feat had been
achieved.
THE work consisted he said, Gin the
placing of substantial iron bridges in the
place of wooden trestle from the upland
at Bergen Hill to point east of Newark
avenue. The location of piers having
been decided upon 1t was found necessary
to build substructure of piles. At each
pier location one or more bents of the old
trestle were removed to clear the space
for piling, and temporary trestle bentS
were placed clear of the pier lines to re-
ceive trussed beams.
"These beams, with span of twenty
four feet, were placed under each track,
and one pair moved at time, thus en-
abling one half of the piles to be driven
for each pier by the blocking of one track
only, crossovers at either end of openings
allowing trains to pass in either direction.
In this manner the substructures for the
several piers were built. The piles were
driven to depth of seventy feet,
generally, and cut off at a depth so that
the capping and flooring upon which the
masonry is built will remain submerged
Under each pier are sixty piles.
''The masonry is what is known as
rock range, or first-class bridge masonry,
laid up in regular courses with Portland
cement. The piers are coped with eighteen
inch brown stone, the upper side or bridge
seat being hammer dressed. The worlc
| on several piers being completed, the
work of placing or laying down on the
ground the iron bridges was commenced.
Pratt type, were built by the Keystone
Bridge Company, originally for use on
the Middle Division, P. H. R., and were
recently replaced with arches or iron
bridges of q heavier pattern at that point.
The bridges were shipped to Jersey City
and laid down, examined thoroughly
and many parts, unfit for further use
were duplicated. Originally these spans,
five of which are liz feet span, with a
height of post of Ii feet, and one of 145
feet span with height of post of seven
teen feet Were composed of three trusses
for double track, but for additional
strength they now consist of four. The
iron being ready the work ON the false
works was started These falseworks
were built on either side of the trestle and
pair of trusses put together thereon.
The ties were placed and the winches put
in position to pull the truss into place.
''Under each pair of end posts steel rails
1oid hn
were pulled into their permanent places
Immediately before pulling in the bridges
the old treStle was cut away. This work
was done on Sundays, at time when
traffic is light, and the actual time taken
in demolishing the old trestle and pulling
one span in place, putting one track in
service, was about three hours, so that
the freight traffic was but little delayed
| in the placing of the several spans.
The plan of pulling in and framing
the bridges on either side held good for
five spans, or until Newark avenue was
Howe trusses, with span of 1877 feet, was
in use.
sit was found necessary at this point to
pull the iron truss in from the north side
the south side falsework being used to
take the wooden span, when it was pulled
out of place. The north falsework sup
ported the iron span for one track. The
wooden truss was cut so that one half
could be pulled to the south falsework,
clear of the tracks, and taken apart,
thus making room for the remaining
north half Of the wooden truss. This
was pulled under the south track, and
the iron span on the north falsework was
pulled under the north track. This left
the north falsework clear and the second
iron span was put together upon it and
will be pulled into position as previously
described. After the bridges are in
position the trusses are fastened to-
gether by joining the top chords. This
work was conducted i'll a careful manner,