Class 334 - bizarre driving style on departure from stations

[Watershed]

I travelled on a class 334 on the Bathgate line recently. It was a dry day, and there hadn't been any rain for some days. So railhead conditions should have been fairly decent.

Yet on departure from every station, I could clearly hear the power being increased, the motors straining against the brakes, with wheelslip occuring, before the brakes would suddenly be released 2 or 3 seconds later. This then invariably resulted in a slight jolt on setting off.

Is this the normal driving style for class 334s? I noticed this both before and after the driver change at Airdrie so it didn't seem to just be one driver doing it this way. It seems a rather bizarre driving style as it's surely wearing out the motor unnecessarily, causing damage to the rail and flats on the wheel, and resulting in an uncomfortable jolt.

It's not even as if it was just happening on stations that are on a gradient. It happened at every single station without fail.

Is this something which ScotRail teach as a normal driving style for the 334? Can anyone shed any more light on this?

Thanks.

 

[TRAX]

Maybe an issue with this particular unit ?

 

[D821]

Maybe an issue with this particular unit ?

That might be the case..
I came home on a Merseyrail 507 or 508 tonight that seemed to he suffering with wheelslip despite it being a dry day and the driver doing nothing unusual.

 

[D6130]

I travelled from Glasgow Queen Street to Helensburgh Central and back this evening - different pair of units and different drivers in each direction - and noticed exactly the same thing. Very strange!

 

[43066]

I travelled on a class 334 on the Bathgate line recently. It was a dry day, and there hadn't been any rain for some days. So railhead conditions should have been fairly decent.

Yet on departure from every station, I could clearly hear the power being increased, the motors straining against the brakes, with wheelslip occuring, before the brakes would suddenly be released 2 or 3 seconds later. This then invariably resulted in a slight jolt on setting off.

Is this the normal driving style for class 334s? I noticed this both before and after the driver change at Airdrie so it didn't seem to just be one driver doing it this way. It seems a rather bizarre driving style as it's surely wearing out the motor unnecessarily, causing damage to the rail and flats on the wheel, and resulting in an uncomfortable jolt.

It's not even as if it was just happening on stations that are on a gradient. It happened at every single station without fail.

Is this something which ScotRail teach as a normal driving style for the 334? Can anyone shed any more light on this?

Thanks.

I have no experience of those units, but that sounds like “hill start” - ie power being applied before brake release to prevent roll back. It tends to be applied at every station as a matter of driving policy.

You wouldn’t expect wheelslip to occur before brake release, though?!

 

[Watershed]

I have no experience of those units, but that sounds like “hill start” - ie power being applied before brake release to prevent roll back. It tends to be applied at every station as a matter of driving policy.

You wouldn’t expect wheelslip to occur before brake release, though?!

Interesting. Why is this considered necessary at stations on level (or near level) track?

Yes, I was surprised at that too. But it was unmistakeably wheelslip!

 

[43066]

Interesting. Why is this considered necessary at stations on level (or near level) track?

It’s generally just applied as a blanket technique on the basis you won’t then forget to apply it where there’s a slope.

It’s completely automatic on some modern units, on various older stock it’s possible to take power with the hill start in and hear the motors straining against the brakes in exactly the way you described!

 

[Towers]

I have no experience of those units, but that sounds like “hill start” - ie power being applied before brake release to prevent roll back. It tends to be applied at every station as a matter of driving policy.

You wouldn’t expect wheelslip to occur before brake release, though?!

Indeed. It'd be more likely that the wheelslip occurs as the brakes come off, due to the excessive power then being put straight through the wheels?

 

[Jturner98]

Could it be that the drivers are using Hill start? Don’t know that particular line or the 334s but we have it on trains in London which holds the train in brake step 1.

 

[43066]

Indeed. It'd be more likely that the wheelslip occurs as the brakes come off, due to the excessive power then being put straight through the wheels?

Possibly, albeit in my experience the motors quickly overpower the brakes if you for some reason take more than minimal power while holding it in.

I can only assume it’s a characteristic of this particular unit. It might even be automatic and outside the driver’s control. Someone who actually signs 334s would be able to confirm.

 

[Watershed]

@scotraildriver ?

 

[MCR247]

It’s generally just applied as a blanket technique on the basis you won’t then forget to apply it where there’s a slope.

It’s completely automatic on some modern units, on various older stock it’s possible to take power with the hill start in and hear the motors straining against the brakes in exactly the way you described!

Do you happen to know if it is automatic on the 700s? I often notice the motors seem to come on briefly before you hear the brakes release

 

[43066]

Do you happen to know if it is automatic on the 700s? I often notice the motors seem to come on briefly before you hear the brakes release

I would have thought so based on how new they are, but can’t say for certain.

@bengley will know.

 

[bengley]

It is indeed automatic, the brakes stay on until power is applied.

 

[Starmill]

Maybe it's that due to the age and some of the known maintenance headaches with them, the brakes don't release as quickly as they ought to on some units?

Some Sprinters seem to struggle with having brakes that are much slower to release than others when setting off. But who knows.

 

[skyhigh]

Some Sprinters seem to struggle with having brakes that are much slower to release than others when setting off.

They are generally very predictable within a class - there are variations between the different classes but I can't say I've ever seen a slower brake release than I expected.

 

[GW43125]

Their DC cousins, the 458s, are similarly abysmal, on many occasions we've braked at 70mph on a dry day and gone into a slide!

 

[scotraildriver]

@scotraildriver ?

Sorry don't sign them

 

[Starmill]

They are generally very predictable within a class - there are variations between the different classes but I can't say I've ever seen a slower brake release than I expected.

Ahhh, I see. That does make much more sense!

 

[hexagon789]

Just to add - 334s have a manual 'hill start' (min brake hold) button on the end of the TBC.

From travelling on 334s over the years, I think it is common practice to hold the button and then select Notch 2 to start away in, releasing the button as the train moves against the brake.