by Gadfly
The old metal lanterns make a good persuader", too! Hit one upside the head with a lantern, he's gonna see stars!
Gadfly
Gadfly
Railroad Forums
Moderator: Robert Paniagua
toolmaker wrote:What makes a plug door so different from a slider. Is it because the door is "drawn in" as it is closed to seal the contents from the weather or theft? Why is an unsecured door a hazard, a few postings mention the doors falling off or fouling the ROW if open. Do the doors swing out if loose?A plug door is MUCH thicker then a standard sliding door because of the design. It has extra bracing and is made of thicker steel to be strong enough and ridgid enough to seal such a large opening under pressure. The added thickness as well as all the associated hardware such as locking arms, gears and housing for the spinner also add to the weight. The shear weight of the doors mean that if enough inertia were created, the door can rip itself off the hinges. If it were to fall off, it could obviously injure or kill someone. When a plug door is opened, it sticks out from car so that it can slide open and be clear of the side of the car. Because of how far it sticks out, it can be a hazard to station platforms and other close clearence areas. Modern track centers will allow a train with an open plug door to pass another train safely, but there is not much more room then that. If two trains passed and each had an open plug door open, they could hit.
Thanks!
Passenger wrote:Do these plug doors have a pressure difference like the plug doors on aircraft?Uh, no. Boxcars are not pressurized.
Cowford wrote:Actually, I think there is one case where boxcars using plug doors ARE pressurized, though minimally: Cryogenic reefers. I'm not overly familiar with loading operations, but I believe liquid CO2 is pumped into the car after closing the doors. I understand these cars have fallen out of favor vs. mechanical reefers as one too many unloaders were asphyxiated upon entering a car that wasn't purged. Unfortunately, the same thing occasionally happens when workers go inside tank cars and tank trucks to clean or repair a tank that was prior purged with nitrogen and not subsequently ventilated.The cryo cars are not pressurized. They are simply filled with Co2 to cool them. But they operate at 0psi. They are not rated as pressure vessels. The door seals would not handle any pressure.
NV290 wrote:Cowford wrote:Actually, I think there is one case where boxcars using plug doors ARE pressurized, though minimally: Cryogenic reefers. I'm not overly familiar with loading operations, but I believe liquid CO2 is pumped into the car after closing the doors. I understand these cars have fallen out of favor vs. mechanical reefers as one too many unloaders were asphyxiated upon entering a car that wasn't purged. Unfortunately, the same thing occasionally happens when workers go inside tank cars and tank trucks to clean or repair a tank that was prior purged with nitrogen and not subsequently ventilated.The cryo cars are not pressurized. They are simply filled with Co2 to cool them. But they operate at 0psi. They are not rated as pressure vessels. The door seals would not handle any pressure.
HoggerKen wrote: It would be hard to say it works at 0 psi. The process is thus, liquid CO² is pressurized, and sent into a compartment at the top of the car, this creates CO² snow. The food product is then loaded into the car, and doors closed. As the snow sublimates, it returns to a gas form. When it returns to gas form, it expands. .
HoggerKen wrote: All the Cryo-Trans cars were converted to mechanical reefers.Not so. I see Cryotrans cars almost daily that are still working off of Co2. And very often they are simply used as insulated plug door cars with no cooling at all. But they are 100% intact with all valves, fitting and fill ports. We get beer cars 5 times a week that are CryoTrans cars.
NV290 wrote:From: http://www.mhwgroup.com/Cryo-Trans.htmHoggerKen wrote: It would be hard to say it works at 0 psi. The process is thus, liquid CO² is pressurized, and sent into a compartment at the top of the car, this creates CO² snow. The food product is then loaded into the car, and doors closed. As the snow sublimates, it returns to a gas form. When it returns to gas form, it expands. .
But the car is not sealed. So excess pressure is vented. Therefore it never operates under pressure. This was an issue early on as people were afraid that if somebody were attempt to open the door that it could injure someone if pressure inside blew it outward. So the cars have pressure vents that do not allow any pressure to develop.
HoggerKen wrote: All the Cryo-Trans cars were converted to mechanical reefers.Not so. I see Cryotrans cars almost daily that are still working off of Co2. And very often they are simply used as insulated plug door cars with no cooling at all. But they are 100% intact with all valves, fitting and fill ports. We get beer cars 5 times a week that are CryoTrans cars.
In 2000, CTI had begun the conversation of their CO2 refrigerated fleet to 64’ mechanically refrigerated railcars with state-of-the-art refrigeration systems and two-way Global Positioning Systems (GPS).I don't see any non mechanical CRYX cars hauling wine these days. I do see system boxes doing the honors. Canandaigua, working through Hub Group for example did use the older CRYX cars prior to being refitted to mechanical as reported in 2003 by Logistics Today. Hub used the UP/CSX "Wine Connection" (since folded under the "Express Lane" umbrella).
In 2003, CTI produced its first run of 100 new 72' interior length mechanically refrigerated railcars.
In the Fall of 2005, CTI ordered 429 additional 72' interior length mechanically refrigerated railcars for 2006 delivery.
HoggerKen wrote:If older CRYX cars are being used, the CO² systems are disabled.That may very well be. All i can tell you is the cars still have the associated piping, valves and labeling for the Co2 system and no mechanical refrigeration of any kind.