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A couple of points to note. 769s actually respond initially quicker, when the driver moves the traction power controller from off to a power notch when starting away from a stand quicker in diesel mode than in electric mode or than a 319 does. Engine revs rise with each notch taken however there is often no discernable rise in engine revs between power notches 3 and 4. As I understand it there is no field weakening in power notch 4 on a 319 when the traction power is supplied in 'DC mode', which is effectively what a 769 on diesel mode is.
I think that I remember that, Once the up train reached about 50mph on the straight beyond Meols Cop, the engine speed was moderate although the speed steadily built up to 73mph. I suppose the generator excitation is adjusted to apply a steady load at the optimum engine rotational speed which is not necessarily maximum HP. The whole ride experience on the 769s is far less hectic than the thrashing of the 150's engines, - even though the cars are very similar.
One other thing that's odd is that the engine revs only really die down to idle when the unit actually comes to a stand. The driver will have shut off traction power long before this (and in any event braking in brake step 2 or more -normal braking on a 319/769- would disable any traction power still applied) but even when coasting with no traction power applied the engines still rev quite high until the train virtually comes to a stand.
A couple of points to note. 769s actually respond initially quicker, when the driver moves the traction power controller from off to a power notch when starting away from a stand quicker in diesel mode than in electric mode or than a 319 does. Engine revs rise with each notch taken however there is often no discernable rise in engine revs between power notches 3 and 4. As I understand it there is no field weakening in power notch 4 on a 319 when the traction power is supplied in 'DC mode', which is effectively what a 769 on diesel mode is.
One other thing that's odd is that the engine revs only really die down to idle when the unit actually comes to a stand. The driver will have shut off traction power long before this (and in any event braking in brake step 2 or more -normal braking on a 319/769- would disable any traction power still applied) but even when coasting with no traction power applied the engines still rev quite high until the train virtually comes to a stand.
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150s etc don't have to be 'thrashed' before the brakes are released. Once the torque converter is actually filled (2-3 seconds) so long as sufficient traction power is applied to overcome any rising gradient, and even on the steepest gradients I drive of 1-in-40-odd, then the unit won't roll back even in just notch 3 power. Lesser rising gradients wouldn't need that much traction power.
Many of us will remember how the compressor slowed down and sometimes the lights dimmed on the old Southern Region slam door units when they started away from a station. Traction packages have to be designed to tolerate these fluctuations.
Even another train entering the same section had a slight effect. I recall waiting for trains coming up the Arun Valley at Horsham. There would usually be an EPB or a VEP humming away on platform 1. When the train coming from Christ's Hospital moved on to the Horsham substation area the note of the motor generator changed so I knew the train was just over a minute away.
Yes 2nd day on trot now, everything on Man to Southport is 2 car unit , plus cancelled services this morning, glad do not commute to Manchester it’s a lottery if going get on train or not
Even another train entering the same section had a slight effect. I recall waiting for trains coming up the Arun Valley at Horsham. There would usually be an EPB or a VEP humming away on platform 1. When the train coming from Christ's Hospital moved on to the Horsham substation area the note of the motor generator changed so I knew the train was just over a minute away.
That sounds like the sort of place that might be a long way from a substation, so even a small extra demand some distance away will cause the voltage to drop noticeably.
Do the 769s have an audible compressor, and if so does anyone have observations on how the note changes with demanded power in diesel mode?
No, that's what I thought it might be at first but it's definitely speed related rather than any auxiliary load, the compressor doesn't really affect engine revs even though it draws quite a lot of current when it runs.
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Yes the main compressor is audible on a 769, it's the same as on a 319 and runs directly off the 750v DV busline and is protected by a 60 amp fuse. Tends to run at a fairly high rate when it starts up, located on the ATS car.
They terminated the ALD to SOP at Wigan Wallgate tonight despite the fact it was running on time. A fellow passenger was bound for SOP but the guard said he knew nothing of any onward connection as he was only told of the termination at Bolton!
Meanwhile, according to RTT an 8 car 769 ran empty from Allerton via Wallgate to SOP
They terminated the ALD to SOP at Wigan Wallgate tonight despite the fact it was running on time. A fellow passenger was bound for SOP but the guard said he knew nothing of any onward connection as he was only told of the termination at Bolton!
Meanwhile, according to RTT an 8 car 769 ran empty from Allerton via Wallgate to SOP
That sounds like the sort of place that might be a long way from a substation, so even a small extra demand some distance away will cause the voltage to drop noticeably.
Do the 769s have an audible compressor, and if so does anyone have observations on how the note changes with demanded power in diesel mode?
They terminated the ALD to SOP at Wigan Wallgate tonight despite the fact it was running on time. A fellow passenger was bound for SOP but the guard said he knew nothing of any onward connection as he was only told of the termination at Bolton!
Meanwhile, according to RTT an 8 car 769 ran empty from Allerton via Wallgate to SOP
On 2nd thought, due to the sub-optimal signalling arrangement since the closure of New Lane and Bescar Lane signal boxes, there won’t have been a spare path for the ECS movement without cancelling the service train, which isn’t exactly ideal!
On 2nd thought, due to the sub-optimal signalling arrangement since the closure of New Lane and Bescar Lane signal boxes, there won’t have been a spare path for the ECS movement without cancelling the service train, which isn’t exactly ideal!
Or very fair to the fare paying end of rush hour customers that were inconvenienced and had their evenings ruined.
Meanwhile, it’s just arrived at Hindley 20 minutes late, which doesn’t auger well for tomorrow!
Or very fair to the fare paying end of rush hour customers that were inconvenienced and had their evenings ruined.
Meanwhile, it’s just arrived at Hindley 20 minutes late, which doesn’t auger well for tomorrow!
I just passed through Southport station to see 769448 in Platform 5 with a 156 either side and was told by staff that it arrived as an 8 car, but the rear set failed on arrival and was detached and taken away again. Then I noticed that while the unit on Platform 4 was running and ready to leave but there was a green signal on platform 6…
I just passed through Southport station to see 769448 in Platform 5 with a 156 either side and was told by staff that it arrived as an 8 car, but the rear set failed on arrival and was detached and taken away again. Then I noticed that while the unit on Platform 4 was running and ready to leave but there was a green signal on platform 6…
448 still sat there this morning on 5. 431 is the 2K82 service which turned up 7 mins late inbound. On board signage doesn't appear to be working either.
Surprise Surprise Northern sent out 769450 on 06:37 Manchester Victoria-Southport service and its now blocking the Atherton line after breaking down at Atherton Station.
Surprise Surprise Northern sent out 769450 on 06:37 Manchester Victoria-Southport service and its now blocking the Atherton line after breaking down at Atherton Station.
And with 431 0716 SOP-ALD borrowed at Salford Crescent for rescue duties thats another one out of service on top the one sat on Platform 5 at Southport. As much as love these commuting on these trains when they work I think someone at Northern or Network Rail needs to make the decision to suspend use of them pending issues being resolved making them reliable.
431 should be back out at some point, it was down to work 2W08 to Southport but that looks to have been caped 2K88 is the return at 1315 so see if it runs! Saying that if only one set is out I would imagine they would end up leaving it, unless they want to really ask for trouble!
And with 431 0716 SOP-ALD borrowed at Salford Crescent for rescue duties thats another one out of service on top the one sat on Platform 5 at Southport. As much as love these commuting on these trains when they work I think someone at Northern or Network Rail needs to make the decision to suspend use of them pending issues being resolved making them reliable.
Whilst I agree that the level of reliability of the 769s is very poor, in the continued absence of the additional 156 sets from East Midlands, there is nothing with which Northern can replace the 769s without extensive shortening of train formations.
Whilst I agree that the level of reliability of the 769s is very poor, in the continued absence of the additional 156 sets from East Midlands, there is nothing with which Northern can replace the 769s without extensive shortening of train formations.
431 should be back out at some point, it was down to work 2W08 to Southport but that looks to have been caped 2K88 is the return at 1315 so see if it runs! Saying that if only one set is out I would imagine they would end up leaving it, unless they want to really ask for trouble!
What happened to the 135s being coupled to 2 car 158s on the Leeds- Wigan NW? Not seen a 153 for weeks.
If they returned on the Leeds route, this could free up some 258s for SOP-ALD
What happened to the 135s being coupled to 2 car 158s on the Leeds- Wigan NW? Not seen a 153 for weeks.
If they returned on the Leeds route, this could free up some 258s for SOP-ALD
158s are surely unsuitable for that route because it gets so busy in the peaks. The relatively large vestibules will extend boarding and alighting times.
What happened to the 135s being coupled to 2 car 158s on the Leeds- Wigan NW? Not seen a 153 for weeks.
If they returned on the Leeds route, this could free up some 258s for SOP-ALD
158s are surely unsuitable for that route because it gets so busy in the peaks. The relatively large vestibules will extend boarding and alighting times.
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