All Things Portal Bridge: Amtrak and NJT Status and Replacement Discussion

fishmech wrote:I do wonder why the PRR hadn't converted its New York City area swing bridges to lift bridges (Including both Portal and the Raritan Bay one). It's my understanding that lift bridges are both more reliable in general as well as easier

Earlier this year I started working for a company that does engineering work (Design, Inspection, Construction Services) related to movable railroad and highway bridges. So some of the maintenance personnel and operators on this bored definitely have more experience living with these bridges.

I can tell you that a lift bridge is generally more complicated and more expensive than a swing span. Wire ropes bring their own expense, and maintenance requirements. The machinery on a swing bridge generally consists of a motor, a brake, a reducer, and a vertical shaft pinion to drive against a rack mounted on the pier. No ropes or drums or counterweights. Either can open or close quickly - this basically just depend on how much horsepower the owner wants to pay for.

Swing spans do require more clearance over the water than other types however, and access for major maintenance usually requires a barge crane.

The bridges are designed for 100 year service lives, and can last much longer. (I inspected a 130 year old span in CT in tip top shape). Mostly, what I've seen, is that the structure needs constant painting, and the machinery needs constant grease if the owner can do that, the bridge will last a very long time.

NJ Transit has awarded $87.7 million worth of contracts to advance replacement of the Portal Bridge to final design.
http://www.recordonline.com/apps/pbcs.d ... 88/-1/NEWS

The fact is Portal Bridge was built in 1907 and opened in 1910. It has reached a full century of service and met its design life. Swing bridge are impractical for two reasons: the narrow channel width they provide relative to lift or bascule bridges and the time for openings.

If you recall Amtrak in 2008 converted the Thames River Bridge in New London, CT from a swing span to a new lift bridge. Closer to here, the NJ Route 7 swing bridge over the Passaic River was replaced with a lift in 2002.

NJ Transit has awarded $87.7 million worth of contracts to advance replacement of the Portal Bridge to final design.

I suppose the new bridge will be 135 feet above the water; that being the maximum height of the (PRR) lift bridges in the area. I wonder what kind of grade that will be from the Lautenberg station?

philipmartin wrote:I suppose the new bridge will be 135 feet above the water; that being the maximum height of the (PRR) lift bridges in the area. I wonder what kind of grade that will be from the Lautenberg station?

That would be wildly inaccurate. The height of the bridges will be 50 Ft. above mean high water. The US Coast Guard will issue new directives and the bridges will become the ruling clearance on the river.

The height of the bridges will be 50 Ft. above mean high water.

That's interesting. I guess there aren't any deep water ships going above portal. We used to occasionally get a ship for Koppers Kearny, between Hack and Portal, but Koppers may not even be there any more. I don't remember if we had ships for other destinations.

Primarily pleasure craft and tugs/barges for Hess and Bergen County Sewer Authority.

Closer to here, the NJ Route 7 swing bridge over the Passaic River was replaced with a lift in 2002.

Actually, the old Rt 7 bridge was a bascule bridge, not a swing bridge.

As for clearances, the Department of Defense no longer requires maximum clearance in many of the local rivers and bays. Once that requirement was eliminated, it becomes much easier to reduce the height of fixed spans. That's why there are now so many fixed spans over the Intercoastal waterway. Until the 1980s, draws were required so that navy ships could use the intercoastal to avoid submarines. In fact, where there were fixed spans, it was required that they contain a section that could be removed to allow over-height ships to pass. Until the AC Expressway was widened, such a span was in place near the NJT rail bridge. There is still a removable span in the 34th St bridge in Ocean City.

philipmartin wrote: We used to occasionally get a ship for Koppers Kearny, between Hack and Portal, but Koppers may not even be there any more.

Koppers is long gone, as is Standard Chlorine. A part of Koppers will be used for a new layover yard as part of the Tunnel project.

Interesting that the plan now calls for the southern-most bridge to be fixed as well. While that makes the most sense to me, the earlier documents called for it to be 40 feet above the water line and a lift bridge. (Current Portal Bridge is apparently 23 feet above the water to put it all in perspective.)

bleet wrote:Interesting that the plan now calls for the southern-most bridge to be fixed as well. While that makes the most sense to me, the earlier documents called for it to be 40 feet above the water line and a lift bridge. (Current Portal Bridge is apparently 23 feet above the water to put it all in perspective.)

Where do you see this? The 'official site' (last I knew) still says a moveable southern span:
http://www.portalbridgenec.com/faqs.html

fredct wrote:

bleet wrote:Interesting that the plan now calls for the southern-most bridge to be fixed as well. While that makes the most sense to me, the earlier documents called for it to be 40 feet above the water line and a lift bridge. (Current Portal Bridge is apparently 23 feet above the water to put it all in perspective.)

Where do you see this? The 'official site' (last I knew) still says a moveable southern span:
http://www.portalbridgenec.com/faqs.html

Some aspects of the official site need to be edited. Suffice it to say that Rail Ops was more than willing to permit a greater grade in exchange for a fixed span.

http://www.metro-magazine.com/News/Stor ... oject.aspx

Suffice it to say that Rail Ops was more than willing to permit a greater grade in exchange for a fixed span.

Sounds like a reasonable trade-off.

fredct wrote:

bleet wrote:Interesting that the plan now calls for the southern-most bridge to be fixed as well. While that makes the most sense to me, the earlier documents called for it to be 40 feet above the water line and a lift bridge. (Current Portal Bridge is apparently 23 feet above the water to put it all in perspective.)

Where do you see this? The 'official site' (last I knew) still says a moveable southern span:
http://www.portalbridgenec.com/faqs.html

Two places: The official NJ Transit press release: "...the new fixed bridges will provide greater reliability by eliminating the need for a movable span." http://www.njtransit.com/tm/tm_servlet. ... SE_ID=2570

Also, from the portal website the latest presentation document indicates two fixed spans without actually saying those words and the drawings show two fixed spans. http://www.portalbridgenec.com/files/li ... _24_09.pdf

Nice looking arch river spans.

I see that they opted to go with more structure rather than embankment. With 29 bridges with 124 spans, it really is a pretty massive project. I wonder though how much more it would have cost to allow for a duck under of the southern western approach spans and a double tracking of the proposed duck under for the northern western approach which would allow for the oft-discussed westbound waterfront connection.