Australia's Bridges: Camellia Railway Bridge across the Parramatta River in NSW

March 2011 (-33.815 deg., 151.026 deg.) Camellia Railway Bridge

The Camellia Railway Bridge has steel legs that wrap around concrete columns to support the long center span of this through truss structure. It's also a very modern truss, having been completed in 1995 making it the newest of the Parramatta River crossings. However, according to the Heritage Council the masonry abutments are unaltered from a 19th century bridge and provide details on early bridge construction in Australia.

Australia's Bridges: Camellia Railway Bridge across the Parramatta River in NSW by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Australia's Bridges: Rydalmere Pedestrian Bridge across the Parramatta River in NSW

March 2011 (-33.818 deg., 151.041 deg.) Rosehill/Rydalmere Footbridge

A kilometer upstream from the Silverwater Bridge is the Rydalmere Pedestrian Bridge.  It's a nice looking two span, through truss bridge on two column bents with a pedestrian walkway between two waterlines. There is also a steep ramp on each side of the bridge to carry water and pedestrians up onto the middle two spans.


The bridge has a rather flimsy looking fender system around the bent in the river. I guess it's a good thing that big vessels don't travel on the Parramatta River anymore.  I have a special fondness for utility bridges and this is a well designed and well constructed structure. I think I'd like to write a book on utility bridges one day.

Australia's Bridges: Rydalmere Pedestrian Bridge across the Parramatta River in NSW by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Movable Bridges - Chef Menteur Railroad Bridge

While we're at the Chef Menteur Highway Bridge, we can look east to see the CSX Railroad Bridge 600 yards away. These two bridges are almost identical (three Warren truss spans) but the railroad bridge has a slightly longer swing span and was built three years earlier (in 1926).

The railroad bridge was also damaged by the hurricane, but it was kept in the closed position, perhaps to allow trains to cross while it was being repaired.

Movable Bridges - Chef Menteur Railroad Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Chilean Bridges: Pasarela Peatonal sobre la Autopista Alessandri

Another pedestrian overcrossing in Concepcion, Chile. It is just northwest of Puente Juan Pablo II over the Rio Bio Bio.

This is a simple Warren through truss with a arched top chord. It looks like a pony truss, which means that it doesn't have a portal frame or any cross bracing on the top.

Chilean Bridges: Pasarela Peatonal sobre la Autopista Alessandri by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Sainsbury Bridges (1)

Continuing on our walk along the River Avon to Bath, we arrived at Sainsbury's Bridges. I wish they wouldn't put two different bridges next to each other because it's hard to distinguish each bridge's features. For instance, in this photo, it looks like the bridge in front has a plastic roof, when it's actually on the other bridge.

The structure in front was a railroad bridge that was converted for highway use after the trains stopped running. I would have called it some kind of lattice truss, except they usually have a roof. Maybe the roof was removed when the bridge was converted to vehicular traffic. The bridge is a two-span steel through truss structure supported at midspan on a large stone pier with cutwaters and on seat-type abutments. Note the big rocker bearings supporting the truss.

Since these bridges provide access to the Green Park Railway Station, I wonder if the pier was the former location of the Midland Road Bridge? The strange thing is that we don't see any sign of where a pier might have been attached to the Midland Road Bridge (in yesterday's photo). Also, it's apparent that the Midland Road Bridge doesn't need a support at midspan. However, there is quite a bit of room on the existing pier where another bridge may have stood.

The other Sainsbury's Bridge is a footbridge supported on three precast I girders. We'll take another look at both these bridges tomorrow.

Great Britain: Sainsbury's Bridges (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Great Britain: Windsor Bridges (2)

The Windsor Bridges were as far as I walked along the River Avon. I often regret not going a little further, because there is usually a beautiful bridge just ahead. That was true in this case as a gorgeous stone arch bridge carrying A4 across the River Avon was a mile downstream and the amazing Clifton Suspension Bridge is 12 miles downstream.

In this photo we are looking back upstream at the Windsor Bridges and the Gasworks Siding Bridge. The Gasworks are visible on the right bank. It looks like the metal frame around the tank supports it as it rises and falls. I understand that two of the three gas tanks have now been removed.

The Whipple truss (on the closer Windsor Bridge) was considered innovative because the diagonal members crossed two panels. In fact, it is sometimes called a double-intersection Pratt truss. It's not obvious (to me anyway) why this bridge is stronger other than more diagonals means more load carrying capacity. The symmetric arrangement of diagonal members must be popular because the Midland Road Bridge also has them. The Windsor Bridge has a single span of about 200 ft so it's pretty strong. This design was used to carry steam locomotives. I couldn't find much information on this bridge but it looks like an older (maybe 19th century) bridge that was in use when the Gas Works were an important part of the local economy.

Since I never made it farther downstream along the locks to Bristol Channel, we'll turn around tomorrow and revisit a few bridges on our way back to Bath.

Great Britain: Windsor Bridges (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Peru's Bridges: Puente Pampa Blanca over the Tambo River

Puente Pampa Blanca (White Prairie Bridge) is a two span though truss on two column bents and seat-type abutments. Each span is 150 ft long and 30 ft wide. The bridge crosses the Rio Tambo about five miles north of Puente Freyne. It carries Route 18, which goes north, crosses the river, and then turns northeast along the east side of this fertile valley (see Google Map).

Using the language we've adopted from The Happy Pontist, this truss only has posts in the 'upward-pointing' triangles. In this photo you can see the floor beams supporting the deck at the bottom of each post and at the point of every 'downward-pointing' triangle. I believe the Happy Pontist explained that the additional posts we often see are there to provide lateral stability to the frame and are not needed when ample cross-bracing is provided to support the compression chord.

We've just looked at three Warren truss bridges. Puente Montalvo is a through truss with posts only in the 'upward-pointing' triangles. Puente Freyne is a deck truss with posts only in the 'downward-pointing' triangles. Puente Pampa Blanca is a through truss with posts only in the 'upward-pointing' triangles. This suggests that when the deck is at the bottom of the truss the vertical tension members are supported by 'upward-pointing' triangles. When the deck is at the top of the truss the vertical compression members are supported by 'downward-pointing' triangles.

In the photo above, we can see that Puente Pampa Blanca was being completed when we visited the site in 2001. If I recall correctly, the only damage from the earthquake was to some steel bearings. I'm not sure why, but I don't find this bridge to be as elegant as Puente Freyne or Puente Rio Sihuas. Perhaps it's just the red paint.

Among the many excellent tools provided by Google (besides this easy-to-use blogging program) is an automatic Spanish to English translator that I've used for the many articles I've read on the bridges of Peru. Of course it's not perfect. Anyway, here is what an article said about the opening of the bridge after Google translated it.

Pampa Blanca Bridge integrated into development. In an emotional popular act was attended by the Minister of Transport and Communications Engineer Luis Chang Reyes, l 29, was inaugurated last September Pampa White Bridge in distritro Cocachacra, an old dream coming true of the whole Province.

Bridge construction Pampa Blanca, whose cost exceeds five million suns, has been executed pursuant to an agreement signed between the private sector represented by the companies Terminal Internacional del Sur Tisure S. A. Central and S. Sugar Chucarapi A. whose combined economic contribution to the contributions of the Provincial Municipality of Islay Municpalidad Deistrital of Cochchacra and Ministry of Transport and Communications have made this work possible, as a clear indication that by entering into with private companies can accelerate the pace of our development.

Hopefully, some slight meaning has been retained. The bridge was made possible by funds provided by local governments and agricultural industries in the area. This ensured that their products could be quickly shipped to world markets. Note the green fertile valley that surround the river and the dry white cliffs on the edges of the satellite photo below.

Peru's Bridges: Puente Pampa Blanca by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.