Not Stopping On A Bridge?
- Thread starter boleyd
- Start date
ColPrice2002
Well-known member
Hi,
Don’t know about other regions, but the South West lines from Waterloo do stop on brides -eg Staines bridge over the Thames, numerous bridges over roads. IIRC, also on the rail bridge over the Tyne at Newcastle.
Don’t know about other regions, but the South West lines from Waterloo do stop on brides -eg Staines bridge over the Thames, numerous bridges over roads. IIRC, also on the rail bridge over the Tyne at Newcastle.
Why would it be "good practice"? In some cases, the Chicago El for example, there would be no choice but to stop a consist on a bridge until the track ahead clears.
I would assume that a bridge that is strong and stable enough to carry the weight of moving consists, with all its motions and vibrations, would also be able to carry the weight of a stationary consist.
You could make the same argument about stopping in tunnels - now I can see the problems of stopping a steam or diesel hauled consist in a tunnel for an extended period but not with electrics. There is one long tunnel here in NSW where loaded passenger trains are not permitted and the crews of all other trains must have respirators in case of a failure in the tunnel.
I can think of no operational reasons for not stopping a consist on a bridge.
This just jogged my memory but there was another tunnel here in NSW on a now long closed coal line where the train crew (driver, fireman, guard/conductor) had to leave the moving train at the tunnel entrance. The driver would have the train moving at a walking speed as it approach the tunnel (in both direction). The train ran without a crew through the tunnel. A new crew were waiting at the other end and would climb aboard as it exited.
Correction:
The tunnel was not particularly longbut the clearance within was so narrow that the crew could not evacuate the train in the case of an emergency. It was not a popular shift with train crews.
The tunnel was actually declared unsafe for crews. Rather than repair the tunnel or immediately close the line this "autopilot" method of working was devised until the coal mine and the line were eventually closed in 1954.
Correction:
The tunnel was not particularly long
The tunnel was actually declared unsafe for crews. Rather than repair the tunnel or immediately close the line this "autopilot" method of working was devised until the coal mine and the line were eventually closed in 1954.
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@boleyd - In PDX, (Portland, Oregon), we have a special case situation with the Steel Bridge, which crosses the Willamette river (Will-ah-met), at a point just south of the two large Willamette riverside freight yards.
The Steel Bridge is the only existing bridge of it's type, in the world > A very high-use double deck, multi-modal crossing with a lift section.
This video featurette, put together by the TriMET agency covers all aspects of the bridge's operations, history and some mild engineering points.
The light rail trains often stop on the bridge, for various reasons, and the lower deck is very, very busy everyday with freight and passenger traffic going all directions.
Trains will often stop on the bridge for extended times during yard to yard shunting, silo transfers and in/out bound strings from the south and north yards and mainlines.
A set of Google Maps Satellite views (at various view angles)
This link shows the bridge, in Google maps > Google maps satellite
Albina Yard on the eastside, and Lake Yard on the west. Westside Freight travels in/out from the Oregon coast along the Columbia/Willamette into Lake Yard, across the bridge and to points east/north.
Amtrak passenger service North/South/East travels across the bridge as well. The upper deck runs Portland Tri-MET light rail on two tracks.
There is also a medium large-ish Silo facility on the north side of the east end of the bridge, and mainline tracks running south on the east side that funnel into the Mainline, east to the Columbia river gorge, and points east, as well as south to Portland's Brooklyn Yard and all mainline points south.
Silo side > GrainCorp Silo
Silo side, east upper deck - Silo side, east upper deck
Eastside Wye to points east/south >East Wye South
East Wye view along footpath > You can clik along the path to see the entire lower deck > Footpath view - East wyes
West side, Upper deck > West upper deck, rail ramps
West side, mainline north to/through Portland Union Station, and points west West side, mainline north
Rico
The Steel Bridge is the only existing bridge of it's type, in the world > A very high-use double deck, multi-modal crossing with a lift section.
This video featurette, put together by the TriMET agency covers all aspects of the bridge's operations, history and some mild engineering points.
The light rail trains often stop on the bridge, for various reasons, and the lower deck is very, very busy everyday with freight and passenger traffic going all directions.
Trains will often stop on the bridge for extended times during yard to yard shunting, silo transfers and in/out bound strings from the south and north yards and mainlines.
A set of Google Maps Satellite views (at various view angles)
This link shows the bridge, in Google maps > Google maps satellite
Albina Yard on the eastside, and Lake Yard on the west. Westside Freight travels in/out from the Oregon coast along the Columbia/Willamette into Lake Yard, across the bridge and to points east/north.
Amtrak passenger service North/South/East travels across the bridge as well. The upper deck runs Portland Tri-MET light rail on two tracks.
There is also a medium large-ish Silo facility on the north side of the east end of the bridge, and mainline tracks running south on the east side that funnel into the Mainline, east to the Columbia river gorge, and points east, as well as south to Portland's Brooklyn Yard and all mainline points south.
Silo side > GrainCorp Silo
Silo side, east upper deck - Silo side, east upper deck
Eastside Wye to points east/south >East Wye South
East Wye view along footpath > You can clik along the path to see the entire lower deck > Footpath view - East wyes
West side, Upper deck > West upper deck, rail ramps
West side, mainline north to/through Portland Union Station, and points west West side, mainline north
Rico
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@JCitron
Well, the bridge has been modeled in Sketchup, and animated by a Chinese modeler.
Animation >>>
It's available on the 3D Warehouse, but would need alot of additional mesh work to add the missing structural details, i.e. barriers, bells lights, then LOD meshes, animation, scripting etc.
The model as is is well organized. Repetitive sections are built as components, so one needs only modify the component and the changes will the apply to all instances of that component.
Rico
@JCitron, @boleyd
This local news special report covers the proposed 4.4 mile subway tunnel that would run under the PDX downtown area.
This is so the blue line can bypass downtown, saving 22-30 minutes of transit time, and take alot traffic off the Steel Bridge, allowing train frequency to go from every 15 mins,
to every 8 minutes.
Back when I lived on the west side of the Portland West Hills, I would ride my bike to work, in combination with the MAX Light rail blue line. (None of the other 4 lines had been built yet)
Since it took so long for the trains to run through downtown, (15 mph on mixed traffic roads, stopping at 8 stations) I would debark at Goose Hollow, the 1st station out of the mountain tunnel, ride across downtown, cross the river on the Broadway bridge, ride east to Martin Luther King Blvd, then catch a northbound bus (with bike rack) to NE Freemont, then ride about 48 blocks to my workplace, wayyyy faster than if I'd stayed on the train. I had an 82' BMW 318 as well, but it was overall cheaper to use TriMET, most of the time.
This local news special report covers the proposed 4.4 mile subway tunnel that would run under the PDX downtown area.
This is so the blue line can bypass downtown, saving 22-30 minutes of transit time, and take alot traffic off the Steel Bridge, allowing train frequency to go from every 15 mins,
to every 8 minutes.
Back when I lived on the west side of the Portland West Hills, I would ride my bike to work, in combination with the MAX Light rail blue line. (None of the other 4 lines had been built yet)
Since it took so long for the trains to run through downtown, (15 mph on mixed traffic roads, stopping at 8 stations) I would debark at Goose Hollow, the 1st station out of the mountain tunnel, ride across downtown, cross the river on the Broadway bridge, ride east to Martin Luther King Blvd, then catch a northbound bus (with bike rack) to NE Freemont, then ride about 48 blocks to my workplace, wayyyy faster than if I'd stayed on the train. I had an 82' BMW 318 as well, but it was overall cheaper to use TriMET, most of the time.
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Missed opportunities are so common with public transit. Boston's Big Dig has the provisions for a North-South connection between North Station and South Station in Boston. The is there and the tunnel is in place but it's not connected, and just as we've had to do for the past 150 years, we have to trek across the city if we're switching from the northside commuter trains to long distance Amtrak out of South Station.