Porterbrook Cl.769 'Flex' trains from 319s, initially for Northern

[jonesy3001]

Are the FLEX trains being refurbished before they hand them to the TOCs?

 

[Mogster]

With the current state of Northern’s recently “refurbished” units we probably won’t notice much improvement...

There is one thing. Travelling on a packed ex Thameslink (?) Northern 319 the other day I noticed the standing provision was much better than on Northern,s 15xs. Handrails extending down from the parcel shelves, vertical poles extending upwards from the seat backs to the ceiling. Much better, I hope that stuff is retained when the are refurbed.

 

[AM9]

With the current state of Northern’s recently “refurbished” units we probably won’t notice much improvement...

There is one thing. Travelling on a packed ex Thameslink (?) Northern 319 the other day I noticed the standing provision was much better than on Northern,s 15xs. Handrails extending down from the parcel shelves, vertical poles extending upwards from the seat backs to the ceiling. Much better, I hope that stuff is retained when the are refurbed.

That's because they were prepared for and intensively used on very busy services. Northern have a lot to learn about providing trains suitable for large volumes of passengers.

 

[Mogster]

Yes. As services get busier Northern need to look at better standing provision, there’s a safety angle also.

 

[507021]

769431 is due out tomorrow apparently.

http://www.realtimetrains.co.uk/train/S60200/2018/12/23/advanced

 

[PHILIPE]

Delete

 

[Bertie the bus]

They're Northern paths. ROG are doing the 769 testing. Surely even Northern wouldn't be stupid enough to accept a train that hasn't even been tested.

 

[jonesy3001]

cancelled til new year

 

[Bertie the bus]

Has it been postponed or was it never scheduled? As the unit only arrived on Friday it looks like somebody noticing some random paths in the system and said it is 769 testing. Did the info come from a reliable source or just some random person on Twitter or Facebook?

 

[507021]

The person who shared it on Facebook is reliable.

 

[Charlie Smythe]

So obviousness the Class 769 are 4 car units. How many of those cars are powered cars and in total how many powered axles are there?

 

[samuelmorris]

The same 4 powered axles as before, in the central power car with the pantograph/transformer. There are two engines, one in each driving vehicle, but they are not in the same location as the traction motors (and therefore powered axles)

 

[gingertom]

So obviousness the Class 769 are 4 car units. How many of those cars are powered cars and in total how many powered axles are there?

driving trailers are fitted with one engine each. All the traction equipment is in the pantograph car, 2x motors per bogie, 4 powered axles.

 

[Charlie Smythe]

driving trailers are fitted with one engine each. All the traction equipment is in the pantograph car, 2x motors per bogie, 4 powered axles.

Thanks for the help.

 

[superkev]

Thanks for the help.

Thats two 390kw (523hp) engines to full 4 cars so performance on diesel prob not too exhilarating. The doner 319 weigh in at around 145 tons.
At a guess with engines fuel etc say 150 tons the 769s will be around 7hp a ton which is same as a 150.
May be of interest.
K

 

[hooverboy]

Thats two 390kw (523hp) engines to full 4 cars so performance on diesel prob not too exhilarating. The doner 319 weigh in at around 145 tons.
At a guess with engines fuel etc say 150 tons the 769s will be around 7hp a ton which is same as a 150.
May be of interest.
K

if the ultimate aim of these units is to work 2* 14x/15x diagrams then it's unlikely these units will ever see much above 90mph anyway.they'll spend most of the time on semi rural routes at no more than 75mph, with the extra being used at mainline connection to improve pathing and reduce blockages.

 

[Charlie Smythe]

The same 4 powered axles as before, in the central power car with the pantograph/transformer. There are two engines, one in each driving vehicle, but they are not in the same location as the traction motors (and therefore powered axles)

Thats two 390kw (523hp) engines to full 4 cars so performance on diesel prob not too exhilarating. The doner 319 weigh in at around 145 tons.
At a guess with engines fuel etc say 150 tons the 769s will be around 7hp a ton which is same as a 150.
May be of interest.
K

Thank you for that. Are the routes that these trains are going to be used on hilly or flat as extreme hills like the Lickey or even the Devon Banks such as the climb from Exeter St Davids to Exeter central could certainly be an issue. Of course those two engines supply power to the middle car which then of course means that they don't contribute to adhesion.

 

[LNW-GW Joint]

Thank you for that. Are the routes that these trains are going to be used on hilly or flat as extreme hills like the Lickey or even the Devon Banks such as the climb from Exeter St Davids to Exeter central could certainly be an issue. Of course those two engines supply power to the middle car which then of course means that they don't contribute to adhesion.

The Northern routes targeted for 769s are quite flat, but the GWR versions will be on the North Downs line which undulates quite a bit around Dorking.
The Thames Valley branches are flat and low-speed.
None of them are planned to go up the Lickey or over the Devon banks.
I guess some of Northern's might find their way across the Pennines from time to time.
The TfW ones due in South Wales may have more of a challenge at the top end of the Valleys.

 

[Gareth Marston]

The TfW ones due in South Wales may have more of a challenge at the top end of the Valleys.

Specifically there going to be used on the Penarth to Rhymney services which is a good old climb from sea level at Cardiff Central to 850 feet in 23 miles. The Penarth branch has some gradients on it too.

 

[61653 HTAFC]

Thought Buxton was one of the planned 769 routes for Northern? That's pretty hilly isn't it?

 

[Mogster]

The Northern routes targeted for 769s are quite flat, but the GWR versions will be on the North Downs line which undulates quite a bit around Dorking.
The Thames Valley branches are flat and low-speed.
None of them are planned to go up the Lickey or over the Devon banks.
I guess some of Northern's might find their way across the Pennines from time to time.
The TfW ones due in South Wales may have more of a challenge at the top end of the Valleys.

Wigan -Bolton- Manchester and Wigan -Atherton- Manchester have some steep bits.

 

[AM9]

Thats two 390kw (523hp) engines to full 4 cars so performance on diesel prob not too exhilarating. The doner 319 weigh in at around 145 tons.
At a guess with engines fuel etc say 150 tons the 769s will be around 7hp a ton which is same as a 150.
May be of interest.
K

The main difference being that the full power of the diesel engines, (less generator/traction electronics losses) will be available at the wheels at all speeds from standstill upwards, and its use only limited by adhesion. With a hydraulic transmission as found on class 150s, power available at the wheel is limited by transmission efficiency until the input/output speeds are more equal. When the diesel engine is run at low speeds there is torque available. It has been suggested here that the 769s, despite having a slightly lower power to weight ratio then the 150s, will have better acceleration - maybe at speeds up to around 40-50mph. When they are running under OLE, of course there is no contest

 

[a_c_skinner]

Thought Buxton was one of the planned 769 routes for Northern?

Buxton was a route used by Porterbrook in their computer modelling of performance (comparable with the DMUs on the route IIRC was the conclusion), but I've not noticed it being suggested in real life. Several people on here have suggested it is a route where adhesion is an issue for a heavy unit with four driven axles.

 

[Charlie Smythe]

The main difference being that the full power of the diesel engines, (less generator/traction electronics losses) will be available at the wheels at all speeds from standstill upwards, and its use only limited by adhesion. With a hydraulic transmission as found on class 150s, power available at the wheel is limited by transmission efficiency until the input/output speeds are more equal. When the diesel engine is run at low speeds there is torque available. It has been suggested here that the 369s, despite having a slightly lower power to weight ratio then the 150s, will have better acceleration - maybe at speeds up to around 40-50mph. When they are running under OLE, of course there is no contest

Although surely the added weight of the engines that are not contributing to adhesion would limit this acceleration even more? For example a 2 car 150 has 4 powered axles for two cars so 50% of the weight is on powered axles, however, as previously mentioned by other after my question regarding this issue, the 769's only have 4 powered axles for 4 cars. So less than 25% of the weight will be on powered axles seeing as the engines are at either end and the motor car is in the middle.

 

[LOL The Irony]

Thought Buxton was one of the planned 769 routes for Northern?

I thought Buxton is supposed to start sharing units with the Mid-Cheshire when Northern get their act together.

 

[childwallblues]

They will obviously have to climb the gradients up to Bryn/Garswood and Thatto Heath when required to visit Allerton but that will be on electric power.

 

[big all]

Although surely the added weight of the engines that are not contributing to adhesion would limit this acceleration even more? For example a 2 car 150 has 4 powered axles for two cars so 50% of the weight is on powered axles, however, as previously mentioned by other after my question regarding this issue, the 769's only have 4 powered axles for 4 cars. So less than 25% of the weight will be on powered axles seeing as the engines are at either end and the motor car is in the middle.

whilst the number off driven axles are important as is the weight off the overall train along with driven axle weight
it not all that important in the grand sceme off things you have more than enough weigh and grip to power the motor coach
you have perhaps 60% power to the motor coach on diesel as compared to a 319 on electric
you will also have an additional say 20 tonnes extra dead weight again not a problem
yes the unit will be perhaps 5-7% less efficient because its dragging an extra say 20 tonnes about but no big deal
in all but the worst adhesion situations no problem will exist
assuming a 319 is perhaps 38 tonnes on a motor coach it will happily power the say 150-170 tonnes with engines off a 769 compared to a diesel loco with perhaps double the axle weight but asked to haul around 500 -700tonnes with minimal wheelslip under normal day to day opperation

 

[Charlie Smythe]

whilst the number off driven axles are important as is the weight off the overall train along with driven axle weight
it not all that important in the grand sceme off things you have more than enough weigh and grip to power the motor coach
you have perhaps 60% power to the motor coach on diesel as compared to a 319 on electric
you will also have an additional say 20 tonnes extra dead weight again not a problem
yes the unit will be perhaps 5-7% less efficient because its dragging an extra say 20 tonnes about but no big deal
in all but the worst adhesion situations no problem will exist
assuming a 319 is perhaps 38 tonnes on a motor coach it will happily power the say 150-170 tonnes with engines off a 769 compared to a diesel loco with perhaps double the axle weight but asked to haul around 500 -700tonnes with minimal wheelslip under normal day to day opperation

So you are saying that it should be fine. Someone told me that the % of total train weight on driven axles is very important.

 

[big all]

i am saying as a driver all be it about 25 years ago
that weight and grip was seldom an issue
yes some locations at some stages in the year may be a problem but in general you knew the problem areas and made allowances
transferring say 400 horse power to 2 axles will never tax the the grip
we used to work a crompton with 9 marinex later bret aggrigate 9 hoppers from tonbridge to salfords or purley at 900 tonnes [918] would struggle to get above 25 on the perhaps 1 in 240 average on the line
the point i am making is people are overthinking things a 50 % increase in weight will be a perhaps 15-20 percent reduction in overall performance

 

[AM9]

whilst the number off driven axles are important as is the weight off the overall train along with driven axle weight
it not all that important in the grand sceme off things you have more than enough weigh and grip to power the motor coach
you have perhaps 60% power to the motor coach on diesel as compared to a 319 on electric
you will also have an additional say 20 tonnes extra dead weight again not a problem
yes the unit will be perhaps 5-7% less efficient because its dragging an extra say 20 tonnes about but no big deal
in all but the worst adhesion situations no problem will exist
assuming a 319 is perhaps 38 tonnes on a motor coach it will happily power the say 150-170 tonnes with engines off a 769 compared to a diesel loco with perhaps double the axle weight but asked to haul around 500 -700tonnes with minimal wheelslip under normal day to day opperation

The class 319/4 weighs approximately as follows:

DTSO - 29 t. tare all seats occupied add 5.92 t. fully crush loaded at 4 passengers per m^2 add 13.696 t.
MSO - 50 t. tare all seats occupied add 6.16 t. fully crush loaded at 4 passengers per m^2 add 14.304 t.
TSOL - 31 t. tare all seats occupied add 5.76 t. fully crush loaded at 4 passengers per m^2 add 13.216 t.
DTCO - 29.7 t. tare all seats occupied add 5.92 t. fully crush loaded at 4 passengers per m^2 add 13.696 t.
therefore the total proportions of weight available for adhesion is: 36% when empty, 34.5% with all seats occupied and 32% with a full crush load (something that regularly happened in Thameslink service)
now add your figure of 20 t. for the new equipment (not sure if it is correct but lets assume that it is), that means that the three figures above become:
31% empty, 30.7% all seated and 29.6 when crush loaded. So in reality, if these modified units ever do reach such heavily loaded levels as they experienced regularly in London and the South-East, adhesion is unlikely to be a severe restriction on their performance.
As has been said several times elsewhere, there is sufficient power to drive them away from a standing start on a 1:29 gradient, so under the wires I doubt whether anything in those areas planning to use them would exceed that even with a permanent possible 20t. deadweight. As for diesel operation, the power available at release of brakes and through much of the acceleration range will be greater than a pair of class 150s.