Do Pendolinos/Class 390s have speed limiters?

[nuneatonmark]

Except for drivers limiting their speed, is there a hardware or software limit on the Pendos of 125mph given they are capable of 140mph? I am aware that in the past many locos (I know that a pendo is not a loco) could and did occasionally achieve higher top speeds e.g. Deltics.

Apologies if this has been asked before.

 

[najaB]

Except for drivers limiting their speed, is there a hardware or software limit on the Pendos of 125mph given they are capable of 140mph?

I believe the 'Speed Supervision' part of the TASS system would prevent overspeed, but am willing to be corrected.

TASS is the Tilt Authorisation and Speed Supervision system, it uses fixed balises on the track which restrict/allow the tilt system and also displays the maximum permitted speed to the driver.

 

[LNW-GW Joint]

Except for drivers limiting their speed, is there a hardware or software limit on the Pendos of 125mph given they are capable of 140mph? I am aware that in the past many locos (I know that a pendo is not a loco) could and did occasionally achieve higher top speeds e.g. Deltics.
Apologies if this has been asked before.

TASS will take control from the driver if there is an overspeed (of 2mph?) above the authorised line speed.
It kicks in where EPS ("Enhanced Permitted Speed") is signed, and always when speed is above the WCML permanent line speed of 110mph.
Once back to the authorised line speed, TASS will then "offer control back" to the driver.
So it's a combination of hardware/software (using the track balises).
The same control system is used on Virgin's Voyagers.

The ATP systems on London-Bristol/Heathrow and out of Marylebone are older and less sophisticated systems but do something similar.
ERTMS as fitted on the Cambrian also does it.
There are no automatic controls on the ECML or MML (yet).
I'm not sure how the MML got away with raising its speed limit to 125mph without having to fit ATP/ERTMS/TASS.
The ECML has "grandfather rights", and will fit ERTMS by 2020, as will the GWML to replace ATP.

 

[notadriver]

I didn't think TASS would intervene at just 3 mph over the limit.

Since Pendolinos don't operate at their top speed of 140 it is the signalling software that limits the speed.

Speeding is a thing of the past these days.

 

[The Planner]

I'm not sure how the MML got away with raising its speed limit to 125mph without having to fit ATP/ERTMS/TASS.

Why? There are 125mph sections on the network without those.

 

[fowler9]

Pendos only have speed limiters when I travel on them. Ha ha.

 

[notadriver]

The main purpose of TASS was to enable tilting, not to permit 125 mph running on the WCML. Elsewhere 125 mph operations took place on the GW and ECML well before ATP or ERTMS were even thought of in the Uk. Why should the MML need ATP etc ?

 

[cjmillsnun]

Why? There are 125mph sections on the network without those.

Agreed, there were 125 sections that just had AWS and were fine for years.
--- old post above --- --- new post below ---

The main purpose of TASS was to enable tilting, not to permit 125 mph running on the WCML. Elsewhere 125 mph operations took place on the GW and ECML well before ATP or ERTMS were even invented. Why should the MML need ATP etc ?

Considering ATP had been around on some european networks since the '50s (look at the Netherlands) that isn't true.

 

[LNW-GW Joint]

Why? There are 125mph sections on the network without those.

As I understand it, the WCML was forced to use TASS above 110mph, as part of the drive for ATP, as well as for tilt control.
I thought the policy was that all new sections of route above 110mph needed ATP, with older routes being retrofitted as they were modernised.
I seem to remember FGW and NR wanted to drop GWML ATP as it was obsolete (and begun only as a trial), but were prevented from doing so by the RSSB as it would be seen by the public as being "less safe" without it.

 

[notadriver]

Agreed, there were 125 sections that just had AWS and were fine for years.
--- old post above --- --- new post below ---




Considering ATP had been around on some european networks since the '50s (look at the Netherlands) that isn't true.

I wasn't talking about Europe have edited my post to reflect that.
--- old post above --- --- new post below ---

As I understand it, the WCML was forced to use TASS above 110mph, as part of the drive for ATP, as well as for tilt control.

I thought the policy was that all new sections of route above 110mph needed ATP, with older routes being retrofitted as they were modernised.

I seem to remember FGW and NR wanted to drop GWML ATP as it was obsolete (and begun only as a trial), but were prevented from doing so by the RSSB as it would be seen by the public as being "less safe" without it.

Don't forget TASS only ensures permanent speed limits are obeyed. To my knowledge it doesn't supervise speed for temporary or emergency speed restrictions, neither does it enforce a braking curve for restrictive signal aspects so is not true ATP. It's mainly for the tilt system.

 

[FordFocus]

I was under the illusion that TASS was simply for the purposes of allowing and telling the tilt equipment how much tilt is required, how long for and at what maximum speed.

Does TASS acknowledge the state of the signalling? If not then it can't be compared to ATP or ERTMS.

 

[Carlisle]

TASS is the Tilt Authorisation and Speed Supervision system, it uses fixed balises on the track which restrict/allow the tilt system and also displays the maximum permitted speed to the driver.

I don't think the TASS system actually displays any speed limits to the driver I believe that's down to their route knowledge, a warning sound and light show when about 3- 4 mph above Maximum line speed

 

[The Planner]

As I understand it, the WCML was forced to use TASS above 110mph, as part of the drive for ATP, as well as for tilt control.
I thought the policy was that all new sections of route above 110mph needed ATP, with older routes being retrofitted as they were modernised.

I don't think that's the case at all, I can think of two routes re-signalled within the last 4-5 years where that hasn't happened.

 

[LNW-GW Joint]

I don't think that's the case at all, I can think of two routes re-signalled within the last 4-5 years where that hasn't happened.

The gist of it, if I remember Roger Ford's article, was that EU rules specify that all primary routes (it might have been just TEN routes) should have ATP over a certain speed.
The requirement was to equip existing routes when the signalling was upgraded, and is now reflected in the ERTMS programme.
I think that is how the WCML came to have the SS part of TASS (the SS is for Speed Supervision).
It was also in the aftermath of Southall (where ATP was fitted but not working) and Ladbroke Grove.
Maybe TPWS gets round all this, having reduced the risk significantly, and I don't think the MML is a TEN route.
Time for Roger to pen an updated article!

 

[driver_m]

To answer the question by the OP yes they do. There is one on the Tms to prevent excess speed over 128mph. There's also the Tass warnings for 3mph over and interventions for 6mph over Eps speeds.

 

[craigybagel]

Might be worth pointing out that almost all locos and units are capable of going faster than their official top speed, and most do not have any form of speed limiters.

Some examples of the few that do are the Siemens desiro family (EMUs will simply cruise at 100/110 mph and not go over even if full power is applied - 185s I believe have the power cut out above 103), and ATWs 158s (the ERTMS will stop the train going much over 90 even on lines where ERTMS is not fitted, or 75 if a slower unit is attached). 175s and I believe 180s have an over speed warning light in the cab but I don't know if they actually do anything other than light up.....

I'd be interested to know if there are any other examples?