Ulrich Buslist Ulrich Forced by more stringent crashworthiness regulations. Without regulatory change most railroads didn't see the need to purchase the more expensive cab... this is why CN was the "lone wolf" for 16 years while everyone else stayed with the cheaper and less safe spartan cab. FRA didn't issue standards till 2006! What regulations are you referring to? Then why did railroads go to the safety cab enmasse beginning in 1989? There must have been some kind of incentive or did they simply have money to burn? Something changed that encouraged a shift away from the cheaper spartan cab... most likely a regulatory change or impending change of some kind.
Buslist Ulrich Forced by more stringent crashworthiness regulations. Without regulatory change most railroads didn't see the need to purchase the more expensive cab... this is why CN was the "lone wolf" for 16 years while everyone else stayed with the cheaper and less safe spartan cab. FRA didn't issue standards till 2006! What regulations are you referring to?
Ulrich Forced by more stringent crashworthiness regulations. Without regulatory change most railroads didn't see the need to purchase the more expensive cab... this is why CN was the "lone wolf" for 16 years while everyone else stayed with the cheaper and less safe spartan cab.
Forced by more stringent crashworthiness regulations. Without regulatory change most railroads didn't see the need to purchase the more expensive cab... this is why CN was the "lone wolf" for 16 years while everyone else stayed with the cheaper and less safe spartan cab.
FRA didn't issue standards till 2006! What regulations are you referring to?
Then why did railroads go to the safety cab enmasse beginning in 1989? There must have been some kind of incentive or did they simply have money to burn? Something changed that encouraged a shift away from the cheaper spartan cab... most likely a regulatory change or impending change of some kind.
Your hypothesis would mean the UP spent money WAY ahead of any deadline given that Norfolk Southern did not adapt widecabs on new road locomotives until, I believe, 1996....
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
BaltACD One thing I have observed through my sports car racing. Impact damage to one corner of a vehicle gets transmitted through the vehicle to the diagonal corner of the vehicle - severe impact to the front of a steam engine will end up affecting the firebox and crown sheets of the boiler - immediately adjacent to the locomotive crew.
One thing I have observed through my sports car racing. Impact damage to one corner of a vehicle gets transmitted through the vehicle to the diagonal corner of the vehicle - severe impact to the front of a steam engine will end up affecting the firebox and crown sheets of the boiler - immediately adjacent to the locomotive crew.
Can we realistically compare the performance of a deliberately light weight under frame to a deliberately (to provide tractive effort) heavy cast under frame?
Remember there is only a single point at which the boiler is rigidly attached to the under frame.
[quote user="Ulrich]
Something changed that encouraged a shift away from the cheaper spartan cab... most likely a regulatory change or impending change of some kind.
[/quote]
How about research by the AAR's Ergonomics Research group that suggested there might be a positive cost benefit situation here. NS slow acceptance shows no immediate regulatory need!
Kyle If you have been in the cab of a locomotive, you would instantly see why. Visibility is really cut down. You can only see one side of the right of way. Curves make this worse. Now think the high short hood is bad, running long hood first is roughly 20 times worse. High short hoods are cool, but not very safe compared to the low short hoods and safety cabs. What I want to know is how much visibility there is when running an SD70ACe long hood forward (eventually one has to back up). Those flared radiators have to really cut down on visibility.
If you have been in the cab of a locomotive, you would instantly see why. Visibility is really cut down. You can only see one side of the right of way. Curves make this worse. Now think the high short hood is bad, running long hood first is roughly 20 times worse. High short hoods are cool, but not very safe compared to the low short hoods and safety cabs.
What I want to know is how much visibility there is when running an SD70ACe long hood forward (eventually one has to back up). Those flared radiators have to really cut down on visibility.
I've been in the cab, and I'm not sure you gain that much operational visibility with the short hood when sitting at the control stand. For high fixed signals, like a block signal on a normal signal pole, yes. For a dwarf or pot signal, signs, switch stands along the right of way, etc, no. You'll lose sight of them at the same time because they will still disappear because of the nose. Sitting at the controls, at best you can see along the top of the short hood. The short hood does let more light into the cab and makes it feel more "open."
I had to run a train for about 30 miles with a SD70ACe running backwards. (The lead engine, brand new, locked up an axle and was set out. They had me run the train to meet a relief crew and a new lead engine.) It was not fun. It was at night, rainy and foggy. I never saw a block signal, had to rely on the conductor for their aspects. That overhang is a big impedient on visibility long hood leading. For GE models as well. Like Zug said, when making switching moves I usually use the mirror.
Jeff
[quote user="Buslist"]
Rumor I heard was that GE and EMD stopped offering to build the standard cabs (or at least without charging a lot of money for them - since only one railroad wanted them).
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
Buslist BaltACD One thing I have observed through my sports car racing. Impact damage to one corner of a vehicle gets transmitted through the vehicle to the diagonal corner of the vehicle - severe impact to the front of a steam engine will end up affecting the firebox and crown sheets of the boiler - immediately adjacent to the locomotive crew. . Can we realistically compare the performance of a deliberately light weight under frame to a deliberately (to provide tractive effort) heavy cast under frame? Remember there is only a single point at which the boiler is rigidly attached to the under frame.
.
The physics of the transmission of force apply no matter is something is built as heavyweight or lightweight - the force of impacts will be transmitted throughout the structure.
Never too old to have a happy childhood!
Everyone, the 1973 CN wide cab ("comfort cab") is not a safety cab! The design was no safer than the standard cab, CN just sought more space for the crew, and mandated appliances such as the hot plate. Note that the first EMD safety cab, the "triclops" has a different design.
Not true.. the CN cab was a safety cab design. It had the posts to withstand over three times the collision impact of a standard cab and the windows redesigned and smaller for safety reasons.
You are correct, I think I was thinking of the cab that the DD40AX has when I posted.
BaltACD Buslist Remember there is only a single point at which the boiler is rigidly attached to the under frame. The physics of the transmission of force apply no matter is something is built as heavyweight or lightweight - the force of impacts will be transmitted throughout the structure.
Buslist
FRA's requirement for high buff strength under frames is a waste? Yes the physics are the same, the way the structure reacts to those forces is what's different. That's why there are things like crumple zones. The structure absorbs it or transmits it or some mixture of the two.
And that doesn't address the point that a boiler on a steam locomotive is only rigidly attached to the under frame at the cylinder sadle.
Before we get too comfortable signing off on the physics is physics school of structural design let's refer to these videos. There is the same impact energy at the contact of the two trains in both scenarios. Both are Budd built cars with almost identical structures although they look a bit different. The physics are the same at this point and throughout the events. The point is how the different structures react to those same laws of physics. The revised consist has energy adsorbing crumple zones (now called crash energy management zones)
I can't get the hot link button on this blog to work from my iPhone (IT HELP PLEASE) but perhaps you can link from this (copy and paste )
<http://youtu.be/NUpUJrk4QBE>
Some of you may have seen some of these impact events ( FRA hates calling them crashes) on Modern Marvels with that bright engineer explaining things.
BuslistBefore we get too comfortable signing off on the physics is physics school of structural design let's refer to these videos [ ... ] The point is how the different structures react to those same laws of physics. The revised consist has energy absorbing [sic] crumple zones (now called crash energy management zones). I can't get the hot link button on this blog to work from my iPhone ...
At least you can post from the phone, which is more than it lets me do most of the time. Try this:
Paul Milenkovic Locomotives can meet particularly heavy and dangerous loads at grade crossings, and there is also the collision hazard with other trains.
Locomotives can meet particularly heavy and dangerous loads at grade crossings, and there is also the collision hazard with other trains.
I'd say the concern is more with grade crossings --- why do gravel loaded semis stall on grade crossings more often than others?
ChuckAllen, TX
cefinkjr I'd say the concern is more with grade crossings --- why do gravel loaded semis stall on grade crossings more often than others?
Probably for the same reason that trailer parks attract tornados.
quote user="CSSHEGEWISCH"]
[/quote]Paul, you seem to be accusing tornados of looking for the easiest places to wreak havoc.[
Johnny
Wait, you drive cylindrical sports cars?
Because a boiler isn't, structurally, a box, the way a car (automobile or rail) is. The shape is going to make a *big* difference in what happens with the force. As is the fact that the boiler is necessarily a *serious* piece of structure, given that it's a big pressure vessel.
Now, collisions *were* known to cause steam-pipe ruptures in the cab (as in "scalded to death by the steam"). But there are steam pipes basically everywhere on a steam locomotive, so the old enginemen may well have been right in thinking they were (on average) safer at the back end than the front.
Peace,--Peter
You might try contacting EMD or GE and asking them. I'm going to go out on a limb here and speculate that market forces may be at work. No one wants to buy a high-hood locomotive. If they did, someone would be building them
Southern Railway purchased high hoods right up until the end with the last being the GP50 units. After the merger with NW the GP59 and the Dash 8-32B units arrived on the property with low short hoods although they were still set up to run long hood forward. As a matter of fact the SD60 units were originally set up to run long hood forward however in later purchases they transitioned the front to the short hoot end. Southern assigned units with the long hood forward for two reasons. First and foremost safety in the event of a head on collision and second, to keep from turning a unit at the end of a run. To this day new NS units are ordered with ditch lights on the long hood end. Crews don't like to run long hood forward but as long as it is not a former CR unit or a hand me down unit from another carrier we can run one backwards if need be. Even the control stands on our units take this into consideration.
Tim G
NS Locomotive Engineer
Only three North American railroads ordered spartan cab SD70s, IC, NS , and Conrail. Conrail's were ordered to NS specifications and went to them in the split. The last orders for high hood units were in 1982. Southern Railway ordered 90 GP50s 7003-7092 and NdeM ordered 9 GP38-2s with high short hoods and steam generators numbered 9901-9909.
Funny thing is there is locomotive not too far distant from me that was built as a low short hood unit, converted to a high short hood and I believe long hood forward configuratio, I'll have to check where the F is.
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