Class 166-performance

[cactustwirly]

In the summer class 166s seem to take an age to accelerate. It is my opinion that it is because the air-con takes away a lot of power from the engine. As they are essentially a modified 165, am I right in saying that the engine wasn't designed to be used with air-con? When they move west how likely is it that they will be fitted with a more powerful Cummins engine that most 158s use.

 

[Bungle965]

In the summer class 166s seem to take an age to accelerate. This is because the air-con takes away a lot of power from the engine. As they are essentially a modified 165, am I right in saying that the engine wasn't designed to be used with air-con. When they move west how likely is it that they will be fitted with a more powerful Cummins engine that most 158s use.

I don't see fgw going to all of the trouble of going to the expense of fitting a new engine, lets not forget that 158s are also very sluggish at there acceleration at high speeds, whereas 165 and 166 are better (compared to a 158).
Sam

 

[RobShipway]

FGW are more likely to put in an air cool system that does not need as much power, like the one proposed to be installed in the future in the class 165s.

 

[sprinterguy]

When they move west how likely is it that they will be fitted with a more powerful Cummins engine that most 158s use.

The engines on the majority of class 158s are rated exactly the same as those fitted to the Network Turbos: In fact, the engines fitted to most of the later built units, 158815 - 862, are the same make and model. Only the final ten class 158s (plus the original 159s) were fitted with uprated 400hp engines, for the Welsh Marches route.

Also, Chiltern's 165s have all been retro-fitted with air conditioning since they were built, and as far as I can tell as a humble passenger it doesn't seem to affect the performance greatly.

 

[VP185]

The 166's do lose a lot of their power in Summer, and a lot is due to the a/c which takes a large amount of horsepower, can't remember the figure that was quoted.
Radiators on a 166 are also at a 45°c angle to the track which means that get clogged with debris and dust resulting in the engine running hot.

 

[LowLevel]

The engines on the majority of class 158s are rated exactly the same as those fitted to the Network Turbos: In fact, the engines fitted to most of the later built units, 158815 - 862, are the same make and model. Only the final ten class 158s (plus the original 159s) were fitted with uprated 400hp engines, for the Welsh Marches route.

Also, Chiltern's 165s have all been retro-fitted with air conditioning since they were built, and as far as I can tell as a humble passenger it doesn't seem to affect the performance greatly.

Entertainingly, the Perkins engined 158s are far and away the most useless of the lot!!

 

[route:oxford]

The 166's do lose a lot of their power in Summer, and a lot is due to the a/c which takes a large amount of horsepower, can't remember the figure that was quoted.
Radiators on a 166 are also at a 45°c angle to the track which means that get clogged with debris and dust resulting in the engine running hot.

How much has been saved (or could be saved) per carriage with LED lighting?

 

[Rich McLean]

166s are power Hungry compared to the 165. In the summer, the air-con works harder, reducing the traction power available. However, units vary in performance, and in most cases it has little effect on time keeping.

 

[pdeaves]

How much has been saved (or could be saved) per carriage with LED lighting?

If LED lighting is anything like LED signals, they consume MORE power [1]. The (financial) savings come from reduced maintenance costs.

[1] I've had to design many a signalling system power modification where the loading was close to the limit... and then 'they' changed the signals to LED types!

 

[Domh245]

I think route: oxford is thinking more about the LED lights compared to the fluorescent bulbs, which will give out less heat, and place less demand on the A/C system as a result

 

[edwin_m]

If LED lighting is anything like LED signals, they consume MORE power [1]. The (financial) savings come from reduced maintenance costs.

[1] I've had to design many a signalling system power modification where the loading was close to the limit... and then 'they' changed the signals to LED types!

Is that because LED signals include a "ballast" resistor to deliberately make them draw as much current as filament lamps, so the lamp proving circuits still work?

Going from fluorescent to LED will maybe halve the power consumption for the same light output, but it's probably less than 1kW per coach so pretty small beer compared to the aircon.

 

[Surreyman]

In the summer class 166s seem to take an age to accelerate. It is my opinion that it is because the air-con takes away a lot of power from the engine. As they are essentially a modified 165, am I right in saying that the engine wasn't designed to be used with air-con? When they move west how likely is it that they will be fitted with a more powerful Cummins engine that most 158s use.

Interesting you should say this as I have been on 166s 4 times in the last 10 days and they all seemed to struggle, I thought maybe an engine was u/s the first time but not on all four journeys.
The 166s are notorious for having unreliable/poor performing air con in the summer months so its kind of a double whammy in the summer - hot 'n stuffy with poor acceleration and unable to reach normal speeds.
Despite all this they are comfortable and I really like them!

 

[Pigeon]

Another point is that engines, especially turbocharged ones, make less power in warmer conditions as the intake charge density is lower. This has readily perceptible effects in everything from cars to aeroplanes.

If LED lighting is anything like LED signals, they consume MORE power [1]. The (financial) savings come from reduced maintenance costs.

[1] I've had to design many a signalling system power modification where the loading was close to the limit... and then 'they' changed the signals to LED types!

This makes no sense at all. LEDs are vastly more efficient than incandescent bulbs. And the difference is even more pronounced for coloured lights, since instead of producing white light and then filtering out (wasting) all the energy in the colours you don't want, you just produce light of the one colour you do want. This is why I designed an LED system for my motorbike to reduce the load on the cruddy underspecified dynamo it has.

I'm not disbelieving you, I'm just wondering what on earth they have done to make a bunch of LEDs less efficient than a filtered incandescent bulb.

 

[notadriver]

In another thread I recollected my trip from Paddington to Thatcham the outbound on an HST/ 165 and returning on a 166. I was pleasantly surprised by the HST which felt very swift compared to the return on the 166. The 166 seemed to really struggle to reach its 90 mph maximum on the fast lines. But I rarely use diesel traction so the whole experience was a novelty.