NJT MLV EMU Procurement

Clear Of BH wrote:

Fan Railer wrote:

Silverliner II wrote:Unless the disk brake is mounted outside of the wheels, Silverliner V (and at one time Silverliner II)-style....

I will venture to say that that design has never been used on a heavy duty locomotive.

Long Island Railroad's EMD DM30AC locomotives are 75 feet long and 298,876 lbs. They have disc brakes and the locomotive is heavy duty. Look for yourself

I don't think that a locomotive with axle loads of 74,719 lbs would be allowed on any railroad. The DM30AC IIRC is significantly lighter than that. Besides, "heavy" and "heavy duty" are not necessarily synonymous.

Clear Of BH wrote:

Fan Railer wrote:

Silverliner II wrote:Unless the disk brake is mounted outside of the wheels, Silverliner V (and at one time Silverliner II)-style....

I will venture to say that that design has never been used on a heavy duty locomotive.

Long Island Railroads EMD DM30AC locomotives are 75 feet long and 298,876lbs. They have disc brakes and the locomotive is heavy duty. Look for yourself.
http://farm9.staticflickr.com/8234/8400 ... 445e_h.jpg

You do not understand the meaning of my post. As you can see by looking yourself, the Silverliner V disk brakes are separate from the wheel and mounted outside of the bolster unit. Any heavy duty locomotive that uses disk brakes will have them integrated into the wheels themselves.

Fan Railer wrote:You do not understand the meaning of my post. As you can see by looking yourself, the Silverliner V disk brakes are separate from the wheel and mounted outside of the bolster unit. Any heavy duty locomotive that uses disk brakes will have them integrated into the wheels themselves.

No, locomotives with disc brakes have separate brake discs - it would be stupid and dangerous to do otherwise.

The steel tires on railroad wheels are wear surfaces, and railroads expect to replace them periodically, so they don't mind using tread brakes that apply pressure onto the tires as well. They would very much mind having to replace the actual wheel regularly, since it is cast in one piece with the axle and other wheel, and not bolted onto an axle like an automobile. Using the wheel as a brake disc would pump massive amounts of heat into a chunk of metal prone to heavy shocks, as well as making that vital part of the wheel thinner over time and causing stress fractures that, inevitably, will cause catastrophic wheel failure and a complete lack of brakes.

In fact, a disc brake outside the truck frame and wheel is the perfect place for it to be regularly inspected and replaced.

mtuandrew wrote:

Fan Railer wrote:You do not understand the meaning of my post. As you can see by looking yourself, the Silverliner V disk brakes are separate from the wheel and mounted outside of the bolster unit. Any heavy duty locomotive that uses disk brakes will have them integrated into the wheels themselves.

No, locomotives with disc brakes have separate brake discs - it would be stupid and dangerous to do otherwise.

The steel tires on railroad wheels are wear surfaces, and railroads expect to replace them periodically, so they don't mind using tread brakes that apply pressure onto the tires as well. They would very much mind having to replace the actual wheel regularly, since it is cast in one piece with the axle and other wheel, and not bolted onto an axle like an automobile. Using the wheel as a brake disc would pump massive amounts of heat into a chunk of metal prone to heavy shocks, as well as making that vital part of the wheel thinner over time and causing stress fractures that, inevitably, will cause catastrophic wheel failure and a complete lack of brakes.

In fact, a disc brake outside the truck frame and wheel is the perfect place for it to be regularly inspected and replaced.

Explain what you see here then:
Vossloh Euro 4000 (heavy duty freight and passenger diesel in Europe):


NJT's own PL42AC:

http://www.railpictures.net/images/d1/9 ... 164736.jpg
VS.
Silverliner V:


As if I needed to say it again, but you can CLEARLY see now that the disk brakes on the Silverliner Vs are independent of the steel tires, whereas the disk brakes on this locomotive are integrated with the tires. Find me ONE example of a locomotive that has disk brakes that are independent of the tires AND are mounted on the outside of the truck. I am willing to bet a small fortune that you will not be able to.

Easy there guys.. Brake it up no reason to fight over brakes

beanbag wrote:Easy there guys.. Brake it up no reason to fight over brakes

No one's fighting. We're just having a conversation about certain design choices.

On locomotives there is no room for inside Brake disks cause Traction motor and Gear occupies the axle between between the wheels.
The Disk brakes mounted on Locomotive wheels are sometimes refered to as cheek brakes.

Haven't found a locomotive yet with the disc outside of the bearing, though the discs aren't necessarily mounted flush with the wheels either. Here's a view of an Acela truck: http://www.railroadpix.com/rrphotos/detail/405.html There are several other non-motored FRA-compatible passenger cars with discs outside of the wheel and bearing, like the Bombardier Bilevel coaches, and the Silverliners were already mentioned.

Otherwise, I misunderstood you earlier - sorry about that. Your statement made it sound to me like you meant a disc was cast in one piece with the wheel, rather than mounted on/next to the wheel. If it actually were one piece, that would cause undue stress on the wheels, but they seem to have an air gap between the brake rotor and the support structure.

Having said that, it seems to me that it's obvious to mount brakes outboard of the wheels for maintenance purposes, but perhaps locomotives don't generally have clearance. Regardless of where they are mounted, it does appear that many of the discs used on passenger cars are made in two pieces so they can be removed without taking off the entire axle.

amtrakowitz wrote:

Clear Of BH wrote:

Fan Railer wrote:

Silverliner II wrote:Unless the disk brake is mounted outside of the wheels, Silverliner V (and at one time Silverliner II)-style....

I will venture to say that that design has never been used on a heavy duty locomotive.

Long Island Railroad's EMD DM30AC locomotives are 75 feet long and 298,876 lbs. They have disc brakes and the locomotive is heavy duty. Look for yourself

I don't think that a locomotive with axle loads of 74,719 lbs would be allowed on any railroad. The DM30AC IIRC is significantly lighter than that. Besides, "heavy" and "heavy duty" are not necessarily synonymous.

ASCHUALLY! I have the the locomotive manual on my bookshelf. I took a glance at the engine specs before making the post to make sure I was correct. That's the locomotives weight.

The Acela truck you show is a Coach truck, not a power truck.

The power car trucks on both Acela and HHP-8 are cheek brakes
see: http://www.trainweb.org/tgvpages/images ... oston1.jpg

DutchRailnut wrote:On locomotives there is no room for inside Brake disks cause Traction motor and Gear occupies the axle between between the wheels.
The Disk brakes mounted on Locomotive wheels are sometimes refered to as cheek brakes.

Actually there is ONE class of locomotive that has disk brakes mounted on the inside of the trucks. Bombardier's ALP platform uses a special design that somehow manages to CRAM everything inside the bolster. Check it out:
http://www.tsb.gc.ca/fra/rapports-repor ... 1d0099.asp

If you look closely, you can see the disks mounted inside the bogie.
http://docs.trb.org/prp/12-1052.pdf - color diagram on page 9

Clear Of BH wrote:

amtrakowitz wrote:

Clear Of BH wrote:

Fan Railer wrote:

Silverliner II wrote:Unless the disk brake is mounted outside of the wheels, Silverliner V (and at one time Silverliner II)-style....

I will venture to say that that design has never been used on a heavy duty locomotive.

Long Island Railroad's EMD DM30AC locomotives are 75 feet long and 298,876 lbs. They have disc brakes and the locomotive is heavy duty. Look for yourself

I don't think that a locomotive with axle loads of 74,719 lbs would be allowed on any railroad. The DM30AC IIRC is significantly lighter than that. Besides, "heavy" and "heavy duty" are not necessarily synonymous.

ASCHUALLY! I have the the locomotive manual on my bookshelf. I took a glance at the engine specs before making the post to make sure I was correct. That's the locomotives weight.

That's easy to say. Of course, everything people post on the internet is true, yes?

So, can anyone else back up the claim that Amtrak is allowing a locomotive with per-axle weight of 74,719 pounds on their property (Penn Station)?

The old Siemens spec sheet that is no longer available did state a weight of 128 metric tons, which is equates to an axle load of 70,500 lbs (although it did not specify a difference in weight between the DM and the DE). Is the weight in the locomotive manual for a locomotive that is fully loaded or whatnot? or is there really a significant difference between the DM's weight and the DE's weight.

128 metric tons is 282,200 pounds.

3000 gallons diesel fuel at 7.15 lb/gallon is 21,450 lb.

Fan Railer wrote:The old Siemens spec sheet that is no longer available did state a weight of 128 metric tons, which is equates to an axle load of 70,500 lbs (although it did not specify a difference in weight between the DM and the DE). Is the weight in the locomotive manual for a locomotive that is fully loaded or whatnot? or is there really a significant difference between the DM's weight and the DE's weight.

The Weight of it empty. The weight difference between the DM and DE30s are rougly 8k lbs. The DM30s have an extra electrical cabinet in the electrical room as well as 3rd rail equipment and other relay crap. The DM30ACs are 298k lb while the DE30s from 405 and up are 291K lb. 400-404 are 5 thousand lbs heavier for unknown reasons.