doesn't the bridge look less tall at one end than the other
near New Brunswick, NJ
greg - Philadelphia & Reading / Reading
Isn't it possibly a swing bridge? Thus one end is cantilevered out, the other end counterweighted?
Part of the Landing Lane Bridge.
http://www.loc.gov/pictures/item/nj1252/
HABS calls it a cantilevered awing bridge:
Cantilever-awing-bridge1 by Edmund, on Flickr
It may have been designed originally to be used as a swing bridge and either was no longer necessary (no navigable traffic) or, more likely, no money.
Cheers, Ed
Doesn't look like it's done much swinging lately.
Henry
COB Potomac & Northern
Shenandoah Valley
I am guessing that awing is a typo and should be swing.
Whether it is or was a cantilever swing bridge, I cannot say but anxious to learn if anybody knows for sure.
Rich
Alton Junction
richhotrainI am guessing that awing is a typo and should be swing.
I agree.
From the HABS data pages:
Along the south bank of the Raritan is the Delaware and Raritan Canal, constructed in 1834 and closed in 1933. Landing Lane is carried over the canal on a plate girder cantilever swing bridge erected in 1920. Beyond the canal, to the south, are residential neighborhoods of single family dwellings and large apartment buildings. On the north (Piscataway Township) side of the Raritan, the immediate area consists largely of wooded parkland. Portions of the park to either side of Landing Bridge contain archaeological remains of Raritan Landing, important during the 18th century as a commercial and trade center.
As of 1982, this was one of five pivot bridges remaining on the entire canal. The bridge was built in 1920, probably following the flood of March 5-6, of that year, the greatest recorded flood of the Raritan (Hunter Research, Inc. 1990:Appendix Ai; Wall 1931:341). Replacing an earlier timber A-frame swing bridge, the pivot bridge was built during the waning years of canal operation.
Regards, Ed
The government link is for a Pratt Truss bridge, as are the pics on that site. There must be three different Landing Lane bridges as this one doesn't look like the other two.
BigDaddyThe government link is for a Pratt Truss bridge, as are the pics on that site.
The Government site covers both bridges, one road, two waterways, the Raritan River and the Delaware and Raritan Canal.
This information is in the Government Data Pages as is the photo (#5) I posted above.
I believe the photo used in your news article is of the "new" 1991 Landing Lane Bridge. The article states that the 2023 bridge will retain the look of the girders of the existing "rickety" bridge.
Landing Lane Bridge is a three span, haunched deck girder structure. It was erected in 1991 to replace the existing steel pratt through truss structure which deteriorated beyond repair. Portions of the stone abutments of the earlier bridge at this location were re-used in the construction.
Thank you, Ed
what seems odd to me is that the bridge span is unnecessarily long. The taller end is the same height for almost half the span before it starts tapering up ... i mean down.
i wonder if it's been repurposed?
Ed you are correct, that was the picture I did not click on.
We know it was a canal although I did not know canal traffic lasted into the 1930's. Because of canal boat traffic, the pivot had to be offset from the middle of the canal. You can see that in the first pic of this thread.
I would think the weight would have to be the same on either side of the pivot. The perspective and angle of the picture may be deceiving. It also looks overbuilt to me too.
gregcwhat seems odd to me is that the bridge span is unnecessarily long.
Well, maybe they tried a shorter one and it didn't quite reach the other bank?
I have to believe that everything balanced at the pivot point. Note the counterweights bolted to the girders at the right, behind the brush. [in the B&W photo]
Repurposed? You mean it was something other than a bridge before it became a bridge? Not sure I follow that reasoning.
I believe after 1933 the pivoting guts were removed and a more permanent abutment installed. This also permitted the water line to pass alongside, too.
[edit] In the blue-painted version it seems the counterweights have been removed.
I've heard the phrase, A Bridge Too Far but not the one A Bridge Too Long
This type of swing bridge was once pretty common along the Atlantic Intracoastal Waterway and other rivers along the Atlantic coast:
https://www.capegazette.com/article/lewes-railroad-swing-bridge-future-still-unknown/194662
And, converting swing spans of any type to fixed bridges when the waterway is no longer in use by boats is rather common throughout history.
And on Maryland's eastern shore I remember both rail and highway bridges of this design.
Sheldon
BigDaddyWe know it was a canal although I did not know canal traffic lasted into the 1930's.
according to the article, the canal was open through 1932. Below is a typical canal bridge, described as "swing bridge"
Chicago has/had a number of asymmetrical swing bridges as well. Some of them rather large.
https://forgottenchicago.com/features/railroads-and-chicago-swing-bridges/
Small or large, they all work the same way, the short end is generally counterweighted or the long end is suspended.
While not as common as center pivot swing bridges, they are/were not rare by any means.
And it clear that the bridge in you photo was once a swing bridge.
gregci wonder if it's been repurposed?
Repurposed in the fact that it is no longer a swing bridge, and used as a stationary bridge, probably.
As far as repurposing, there are many companies that sell flat cars and TOFC for bridges.
http://www.sterlingrail.com/classifieds/index.php
Mike.
My You Tube
ATLANTIC CENTRAL Chicago has/had a number of asymmetrical swing bridges as well. Some of them rather large. https://forgottenchicago.com/features/railroads-and-chicago-swing-bridges/ Small or large, they all work the same way, the short end is generally counterweighted or the long end is suspended.
richhotrainI don't see anything in that limk that looks even remotely like the bridges in greg's and Ed's posts.
I only saw a photo of one that looked like a plate-girder type cantilevered swing bridge. They refered to it as the Z-6 Bob tail swing bridge.
The swing bridge was the dominant drawbridge design for Chicago and the nation from the mid-1850s through the 1890s.
A second, not nearly as well known swing bridge exists about a mile north of the Z-2 Bridge at a bend in the North Branch roughly one block south of Cortland Street. Built in 1899 also by the Chicago, Milwaukee & St. Paul Railway, this bobtail swing bridge is still operable due to its very low river clearance. Usually left in the open position, it is still used to move train carloads of recycling from scrap metal dealers on the east side of the river.
At just over 175-feet long, this may be the longest plate-girder swing bridge ever built, as established engineering standards generally limit such spans to 150 feet.
The rest were various designs of lattice-type cantilevered swing bridges. Interesting just the same.
Yeah, as a lifelong Chicagoan, I love the Forgotten Chicago links. Unfortunately, Chicago has a love affair with tearing down structures that should be treasured as national landmarks. But it is pretty difficult to tear down the bridges, thank goodness.
a few miles west is a railroad bridge described as a swing bridge that rotates. Currently maintained as a foot bridge
it might be worth noting that along this section of the river, long before the canal was built, Washington's soldiers were encamped. On July 4, 1777, the soldiers fired their muskets in seccession down the river to celebrate the first anniversary of the signing
gregc
Greg, the bridge you posted a picture of also original rotated, just one end was short and counterweighted while the other end spanned the canal.
Did you click on the first link I posted? It shows an areal view of this sort of bridge.
That is why they appear longer than they need to be, the shore line is partly cut down or cut back to allow the "Bob tail" of the bridge to swing.
richhotrainYeah, but that bridge bears little resemblance to the one shown in your initial post, greg.
i agree. seems like there are many types of "swing" bridges. some swing up, some swing around.
and while a swing bridge may have spanned the canal in the orignal photo, i doubt that steel bridge ever "swung". there was certainly no need after 1932
i wonder if it's half of an old turntable bridge
Probably an optical illusion, but the right side of the bridge in your initial post seems to be falling away from the left side of the bridge in the photo.
I remember reading, perhaps in Trains magazine, about a bridge built over what was technically (but not in actual practice) a "navigable stream" so the railroad by law had to build a movable bridge, swing or bascule or lift or whatever. They moved it once to satisfy the Coast Guard that "see, it moves." It never moved again and never needed to. The technical requirements had been satisfied. Similarly Harold Russell's multi part series on bridges in Model Railroader many years ago mentioned a bridge that had its motor removed so only a hand crank was left should it need to be opened.
I was looking yesterday at a large binder of archives bridge material that the Chicago & North Western Historical Society reprinted years ago and many bridges over rivers and streams were described as "movable bridge" but "no longer operated." This makes me suspect that it is fairly common for bridges over water to have to be of a movable sort, but not actually moved often if at all.
Dave Nelson
gregcseems like there are many types of "swing" bridges. some swing up, some swing around.
From what I understand, lacking an engineering degree, a swing bridge does "swing" or pivot.
If it swings "UP" it would be a lift bridge?
richhotrainProbably an optical illusion, but the right side of the bridge in your initial post seems to be falling away from the left side of the bridge in the photo.
I believe that is part of the design to lighten the weight at the far (cantilevered) end of the span.
We still have a venerable swing bridge here in Cleveland on the Cuyahoga River. It is also a cantilevered type and has un-equal spans on each side of the pivot point.
The New York Central main line crossed the Cuyahoga River on this swing bridge which was replaced in 1956, by the vertical lift bridge, which is still in use today.
NYC_1956-swing-bridge by Edmund, on Flickr
gregc richhotrain Yeah, but that bridge bears little resemblance to the one shown in your initial post, greg. i agree. seems like there are many types of "swing" bridges. some swing up, some swing around. and while a swing bridge may have spanned the canal in the orignal photo, i doubt that steel bridge ever "swung". there was certainly no need after 1932 i wonder if it's half of an old turntable bridge
richhotrain Yeah, but that bridge bears little resemblance to the one shown in your initial post, greg.
Just based on the photo, and similar bridges I have seen up close, it seems much more likely that it did swing at some point and later the piers were rebuilt to make it fixed.
A bridge like that could easily date from the teens, or a little earlier and then been rebuilt in the 30's or later.
Here where I live, the ex PRR, now AMTRAK, crosses the Susquhanna River with swing span.
They still open it from time to time to get large equipment barges to the town of Port Deposit.
To do so is a major operation, because the rails are fixed at the swing span joints for the 88 mph AMTRAK traffic.
So a crew must unbolt the rails of both tracks and reconnect them when the span closes.
ATLANTIC CENTRAL it seems much more likely that it did swing at some point
From the Historic American Building Survey —
Landing Lane is carried over the canal on a plate girder cantilever swing bridge erected in 1920.
The canal is crossed by a steel girder cantilever pivot bridge south of Landing Lane Bridge. As of 1982, this was one of five pivot bridges remaining on the entire canal
You can read the full text of the history here:
http://cdn.loc.gov/master/pnp/habshaer/nj/nj1200/nj1252/data/nj1252data.pdf
[quote user="gmpullman"]
Seems right to me, (particularly with your documentation of this particular bridge ).
ChuckAllen, TX