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Bridge Structure Glossary
Bridge Structure Glossary
To help understand the terms used in civil engineering to describe various structures used in bridge construction, this glossary has been created. As of Feb 8, 2020, this is the first version of it with terms derived from the article Canadian Railway and Marine World - 1914-11 - Extensive Improvements on the Dominion Atlantic Railway, P490
Aboiteau
A type of dyke with gravity and pressure controlled automatic drainage gates or check valves that allows water to drain to the sea but keeps seawater from flowing back under the dyke. While maintenance is needed, no attention is required for each change of the tide. See for example https://en.wikipedia.org/wiki/Aboiteau#/media/File:Dam_slit_2D-en.svg
Concrete Rail Top Culvert
A small concrete culvert with the rails and ballast laid directly on top - would look like a small concrete bridge. It may or may not have a paved bottom. This is not a common usage. Most culverts are much lower than the railway bed.
C. I. P. or Corr. I. P.
Corrugated Iron Pipe culvert, made of rolled iron (probably really steel) sheets with corrugations.
C. S. S. P.
Corrugated Structural Steel Plate pipe, similar to C.I.P. above, but CSSP is usually larger and may be assembled on-site.
D.T. Span
A "deck truss span".
D.P.G. Span
A "deck plate girder" span. The deck is high, at the top of the girders. https://en.wikipedia.org/wiki/Plate_girder_bridge#/media/File:PlateGirderUnderTracks.jpg
D.P.S. Span
A deck plate swing span, seen at the South Maitland Bridge as shown at the left side. The axis of swing is above the first "o" in the word "Collection" on the picture.
D.S. Span
A deck (girder or plate) swing span. The example given is the replacement for the old bridge at Big Joggins. The second South Maitland bridge and the Sissiboo River bridge had similar mechanisms.
The original Big Joggins Bridge
The replacement Big Joggins Bridge
Deck Truss Bridge
A truss bridge with the roadway/railway on top of the trusses. This allows multiple cross bracing under the roadway/railway which can then be more compact for the same strength as other types. The downside is more clearance above the water or whatever passes underneath is needed. An example: https://en.wikipedia.org/wiki/Truss_bridge#/media/File:ErieCanalRRBridge04_1A.jpg
The second Bear River bridge is pictured below. At the far end is a plate deck girder span, then a deck truss span that swings (swing span), then three 156' truss spans, then two more deck girder spans.
Train No. 98 on the Bear River Bridge
H.D.P.G. Span
A "half deck plate girder" span. The sides are plate girders with the deck about halfway between the top and bottom of the girders. See the part of the RR bridge (where the train is) pictured below. Notice the rails are hidden behind the side of the girders, but at not all the way down to the bottom of the girders.
H.T.G. Span
A (possibly?) half truss girder - a truss bridge with the deck about halfway between the top and bottom of the truss. Alternately, a span with a combination of plate girders between trusses. The article cites the Gaspereau Bridge, but the spans there in 2010 were two through trusses and two half deck plate girder spans. Perhaps the half deck spans were done later than 1911. An example is at the two trusses at the St. Croix bridge.
St. Croix bridge
Lattice Girder
A type of truss, usually constructed of many small members close together. The first Windsor bridge was a lattice bridge. They are distinguished from other truss bridges by the number of small members and the overlap between them. Other trusses are more open, such as the highway adjacent.
Lattice Member
A beam or column made up of smaller pieces in a lattice. These are often seen as part of a larger bridge. An example is the parts of the Bridgetown bridge.
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Lift Span
A movable bridge that is raised to allow ships to pass beneath.
Overhead Highway Crossing
A wooden trestle for an elevated roadway to cross a railway track.
P.G.D.S. Span
A "plate girder deck span"
R.C.C.
Reinforced Concrete Culvert
S.B.
Stone Box culvert, size in feet and inches, a rough dressed stone culvert with flat stone slabs laid at the top and bottom. "Double" indicates two of the same, side by side.[1]
A Stone Box (S.B.) culvert at Hillaton, April 20, 2008
T.P.
A Tile Pipe culvert which uses a ceramic pipe made of vitrified clay held in place by stonework walls.[2]
An 1880s Tile Pipe (T.P.) culvert at Sheffield Mills, April 20, 2008.
Surface cattle guard
A cattle guard at a crossing (possibly?) like this: https://en.wikipedia.org/wiki/Cattle_grid#/media/File:Rail_cattle_guard.jpg with no deep pit beneath it. While a pit cattle guard has more space below the rails, as at https://steelcattleguards.com/collections/all/products/blm-cattle-guard-grid-hs-20
Swing Span
A movable bridge that rotates about a vertical axis to allow ships to pass to one side or the other.
T.P.G.
A through plate girder, where the rails are carried low down between the plate girders, such as seen in the nearest span at the Allain River bridge at Annapolis Royal
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T.T. span
A "through truss" span, such as at Bridgetown bridge over the Annapolis River.
Through Girder Span
As seen below. Note the rails are at the bottom of the girders.
Truss span
A truss bridge between two piers or abutments. So a multi-span bridge might have say, two abutments, one each end, and three piers (free-standing towers), with four "spans" where a span is the distance between a pair of piers or between a pier and an abutment.
W.B.
Wooden Box culvert, often 1 foot by 1 foot.
