[nfitz]

You expect them to reliably turn the trains around in 2 minutes? Good luck with that.

Trains are given a 8 minute layover at Union, and 17 minutes at Pearson.

I did expect them to be able to turn around in about 2-3 minutes at one end of the line - with step back crewing.

I'm curious what the standards are in Europe, per se, for turn-arounds.

I wonder if the original equipment purchase was predicated on only using 4 trainsets at once. It seems to me they should have ordered 21 cars, not 18 for a 15-minute service.

 

[drum118]

I did expect them to be able to turn around in about 2-3 minutes at one end of the line - with step back crewing.

I'm curious what the standards are in Europe, per se, for turn-arounds.

I wonder if the original equipment purchase was predicated on only using 4 trainsets at once. It seems to me they should have ordered 21 cars, not 18 for a 15-minute service.

Had a chance to watch Frankfurt U4 & 7 end terminal as well a number of other ends of line service including intercity service and it was about 5-7 minute turn around last year. Even for buses. No step back crews on site.

Spare ratio would say ML needs 3 cars off line leaving 15 for service

 

[reaperexpress]

No, they don't have regenerative braking, as that would require electric traction motors, which they don't have. Generally with railroads, the term "regenerative braking" is used to describe a system whereby an electric vehicle returns power back into the grid, whereas in "dynamic braking" the electricity generated by braking is converted to heat.

They do use a retarder, which is a device that is mounted on the driveshaft and slows the wheels down via the driveline. This is common on buses and trucks as well.

Numerous sites claim that the Nippon-Sharyo DMU has regenerative braking, probably copying from wikipedia:

The cited source is the requirements that SMART set out when ordering their Nippon-Sharyo DMUs.

The power from the braking system does not need to reach the grid in order to be considered "regenerative", it just needs to be used in some productive way rather than burning it off through resistors. For example, electric cars have regenerative braking even though that power never reaches the grid.

 

[Bordercollie]

Numerous sites claim that the Nippon-Sharyo DMU has regenerative braking, probably copying from wikipedia:
View attachment 456848

The cited source is the requirements that SMART set out when ordering their Nippon-Sharyo DMUs.
View attachment 456849

I don't know how crews operate the trains but would better utilization of the dynamic braking save the disks and prolong their life?

 

[lenaitch]

No, they don't have regenerative braking, as that would require electric traction motors, which they don't have. Generally with railroads, the term "regenerative braking" is used to describe a system whereby an electric vehicle returns power back into the grid, whereas in "dynamic braking" the electricity generated by braking is converted to heat.

Tnx. I was just going on the Wiki entry that Reaperexpress is quoting.

They do use a retarder, which is a device that is mounted on the driveshaft and slows the wheels down via the driveline. This is common on buses and trucks as well.

You mean an engine brake ('Jake Brake'). Did not know that. Tnx.

Regardless, the discussion started with a post about using dynamic braking, and my position is that I doubt they are so equipped.

 

[Bordercollie]

Tnx. I was just going on the Wiki entry that Reaperexpress is quoting.


You mean an engine brake ('Jake Brake'). Did not know that. Tnx.

Regardless, the discussion started with a post about using dynamic braking, and my position is that I doubt they are so equipped.

Did you not read the post above?

 

[smallspy]

Numerous sites claim that the Nippon-Sharyo DMU has regenerative braking, probably copying from wikipedia:
View attachment 456848

The cited source is the requirements that SMART set out when ordering their Nippon-Sharyo DMUs.
View attachment 456849

The power from the braking system does not need to reach the grid in order to be considered "regenerative", it just needs to be used in some productive way rather than burning it off through resistors. For example, electric cars have regenerative braking even though that power never reaches the grid.

If they do in fact have such a device (none of my paperwork for the UPX units indicates it, although an absence of information does not indicate that they are not equipped).....

An invertor providing onboard power would not be able to fully recover all of the braking power generated by the train. Yes, a portion of the braking would be considered regenerative in this sense.

In the case of the UPX units, they do absolutely have a retarder (I can't recall a model number at this moment) to provide the bulk of the braking force at most speeds. The transmission on the SMART units does also normally have a retarder, so in that case it too would be providing the bulk of the braking force.

You mean an engine brake ('Jake Brake'). Did not know that. Tnx..

I didn't, actually. A Jake Brake is another way of doing the same thing, and uses fewer components to do it. Its primary disadvantage is a lot more noise, and a little bit less fine control.

Dan

 

[W. K. Lis]

Reminds me of these signs...

From link.

Engine brakes, also known as “Jake Brakes,” are an important piece of safety equipment for commercial vehicle operators. Trouble is, they can cause an irritating pulsating noise when combined with modified engine exhausts.

In fact, a few comparisons we’ve heard people use to describe the rattling “blat-blat-blat” sound include:

• a machine gun
• a jackhammer
• a woodpecker drumming on a chimney pipe (the birds do this to establish a territory and attract a mate, by the way)

There’s even a common term coined for the sound: the “Jake Bark.” And you bet we receive letters of concern from residents near highways that use these, and many other creative similes, when reporting high noise levels coming from trucks travelling through their communities.

But the fact remains: engine brakes improve braking capabilities on trucks, increasing their overall safety, which results in improved safety for all travellers.

 

[Allandale25]

 

[Bordercollie]

View attachment 457719

With no trains available how are they going to do that?

 

[T3G]

With no trains available how are they going to do that?

Clearly they must have trains available.

 

[SaugeenJunction]

With no trains available how are they going to do that?

They fixed the issue, the full power of the UPX may now be unleashed.

 

[ShonTron]

It seriously needs later service too from Pearson. Right now the last departure is 11:27 pm, which is too early for many of the late flights coming in, especially once passengers get off the plane and go through customs and retrieve bags.

 

[DSC]

With no trains available how are they going to do that?

Now, Mr Collie: We KNOW you can do better:

I think one must assume that MLX have fixed the wheel problem and are back to having sufficient trains.

 

[Bordercollie]

Now, Mr Collie: We KNOW you can do better: View attachment 457725

I think one must assume that MLX have fixed the wheel problem and are back to having sufficient trains.

You say that but they have made other announcements and it turns out that it was a case of broken telephone. Just saying.