Electric trucks - interesting trial

[marconi]

I found this interesting trial on electric trucks.

 

[marconi]

I have to admit that did go through my mind when watching the video.
IIRC they talked about "tram voltages", and I assume that means something in the order of 500V DC. If they split the rails +/-250V then that's gone a long way to reducing the risks.
But unlike trams, they aren't connected by metal wheels to an earthed metal rail - so I could see there being a risk if the insulation fails. I guess these would have to be Class II double insulated since there's no means t provide a reliable earth.

Also, there were some clear images of the tops of the collector pick-ups - complete with significant wear grooves in them. On railways, the overhead lines weave side-side so that the pick-ups wear across a significant part of the width and the wire never rubs in one place for any length of time. Otherwise, it wears grooves in the pick-up contacts (IIRC graphite blocks help in place by vacuum on trains) and then causes problems allowing the wire to move side-side easily.
I wonder if the driver had been following the wires - because I did notice them weaving in the same way as for railways which should have avoided the grooves.

Also intersting to consider the currents involved. If we assume (for simple mental arithmetic) 500V DC, then that's 2A/kW, or 1.5A/hp. Given that trucks are generally in the "hundred of hp" range - 500hp+ not being uncommon - then there's significant currents involved. I know it's going to be lower when cruising along the motorway, but they'll also be re-charging to cater for when they've been off the network. So probably need to allow "a couple of hundred amps" per truck minimum, and we've seen how close some trucks can follow each other !

From the video I 'think' power is injected to the overhead lines at regular intervals; perhaps this power is transformed down from a higher voltage. For me the quoted voltage is too low to be efficient. I guess the trial, as stated in the video, had the address the fire brigade's and police's concerns about a higher voltage over a busy motorway.

One can imagine trucks forming up as a line and 'cleverly' sharing their onboard battery and motor power so as not to overload a section of overhead line or when going up hill.

As an aside but has some relevance I understand the electric robot cranes at the Thames Gateway port near me co-ordinate their lifts and drops - this could happen on the motorway between trucks.

Inside the ground-breaking sea port on the Essex coast you never knew existed - https://www.essexlive.news/news/essex-news/inside-london-gateway-uks-most-4507792

Inside the London megaport you didn't know existed - https://www.theguardian.com/artanddesign/architecture-design-blog/2015/sep/15/london-gateway-megaport-you-didnt-know-existed-docks

 

[Simon47]

What about if each truck pulled more than one trailer and to keep them within the area of the overhead they ran on some sort of metallic track system...

Nah, it'll never catch on ?

From the video I 'think' power is injected to the overhead lines at regular intervals; perhaps this power is transformed down from a higher voltage.

That is the normal way of doing it - the intervals depending on various factors.

For me the quoted voltage is too low to be efficient. I guess the trial, as stated in the video, had the address the fire brigade's and police's concerns about a higher voltage over a busy motorway.

Yeah, could you imagine the discussions ...
Lecky truck people: We're planning on putting bare lecky wires over the motorway, right where they'll fall on the road if they break. Oh yes, and for efficiency we're going to make them high voltage ... lets see <stick finger in air> a few kV should do it. That won't bother you when dealing with an accident will it ?
Fire and Police: F*** that pal !

One can imagine trucks forming up as a line and 'cleverly' sharing their onboard battery and motor power so as not to overload a section of overhead line or when going up hill.

As an aside but has some relevance I understand the electric robot cranes at the Thames Gateway port near me co-ordinate their lifts and drops - this could happen on the motorway between trucks.

That's a bit easier when it's a closed system and everything is under your own control.
It does remind me of a story my late father used to tell. He started his career when Nottingham still had trollybusses - and he used to say he could tell when something was going up Corporation Hill by the ammeters in the substation going up. This was just about the time when they were starting to phase them out for diesel busses that belched black smoke instead.

 

[marconi]

This is engineering.......I love it.

Rather simple but what struck me about the video were three things:

1. that the driver could steer a 40 odd ton HGV with his finger;

2. how quiet and comfortable it was in the cab;

3. how little vibration.

 

[Simon47]

Rather simple but what struck me about the video were three things:

1. that the driver could steer a 40 odd ton HGV with his finger;

That's normal with modern over-assisted steering. IMO modern cars, and I assume trucks, have gone too far in lightening the controls - makes it interesting switching between and old car (heavy controls) and a new one (light controls).

But if you look at the arrangement of an artic, the steer wheels really don't do anything to the trailer. They just turn tbe tractor, and the trailer just follows as the coupling is on top of the tractor rear axles. So that leaves turning the tractor which weighs a few tons - but power assistance takes care of that.

 

[ipf]

Rather simple but what struck me about the video were three things:

1. that the driver could steer a 40 odd ton HGV with his finger;

2. how quiet and comfortable it was in the cab;

3. how little vibration.

I suppose there could be some sort of automatic steering system, for keeping in line …all that talk of doing them in cars a while back. Probably control speed too, these days.
3. German roads for you.

 

[Deleted account]

Hindsight.. When I were a Lad.. Newcastle was full of Trolley Busses.

Edit. Plus, that machine in my avatar was electric.

Your older than me coz I don’t remember them. I’m 49.

ive seen photos from the 1800s with tram lines down the key side. Is than when you mean.

 

[marconi]

What about if each truck pulled more than one trailer and to keep them within the area of the overhead they ran on some sort of metallic track system...

It works in Australia:

Perhaps we could have them here but restricted to running during the quiet over night hours along the motor way network. It would ease the driver shortage.

 

[Simon47]

You don't need to go down under to see large loads on the road. We move submarines about up here :

They also move the whole boat (7,400t) when it's fully built - but that's not on the road ! Literally just pick it up and trundle it along.

The next class of boats is a lot bigger.

 

[ruston]

Your older than me coz I don’t remember them. I’m 49.

ive seen photos from the 1800s with tram lines down the key side. Is than when you mean.

Yes , quite a bit older than you. It was around the late 50's 60's , probably before that too.
They looked like ordinary double decker busses with a similar set up to the op.

 

[Deleted account]

Yes , quite a bit older than you. It was around the late 50's 60's , probably before that too.
They looked like ordinary double decker busses with a similar set up to the op.

That was amazing. Struggled to recognise many land marks TBH. Things have changed so much in the last 60-70 years.

in fact I haven’t been back to Newcastle for over 10 years. Going back in couple of weeks. I probably won’t recognise it.

 

[ruston]

That was amazing. Struggled to recognise many land marks TBH. Things have changed so much in the last 60-70 years.

in fact I haven’t been back to Newcastle for over 10 years. Going back in couple of weeks. I probably won’t recognise it.

I don't go much either , but much of it is still the same , but with the usual modern updates and one way systems.
The RVI is still one of the best hospitals in the country, and the Freeman is still going strong.

 

[Deleted account]

I don't go much either , but much of it is still the same , but with the usual modern updates and one way systems.
The RVI is still one of the best hospitals in the country, and the Freeman is still going strong.

Absolutely agree on the hospitals front.

 

[ruston]

Absolutely agree on the hospitals front.

Without a doubt . I have first hand experience of the Freeman. They are incredible. My Macmillan nurse and team were beyond belief .

 

[UNG]

But if you look at the arrangement of an artic, the steer wheels really don't do anything to the trailer. They just turn tbe tractor, and the trailer just follows as the coupling is on top of the tractor rear axles. So that leaves turning the tractor which weighs a few tons - but power assistance takes care of that.

There are quite a few trailers about that have steering axles so they can get round the tighter corners

 

[nicebutdim]

There are quite a few trailers about that have steering axles so they can get round the tighter corners

A local company were granted a Vehicle Special Order to conduct road trials on a 50+ ft trailer. At the time it was a UK first, but no idea what happened with it. Even with the extra length, it could turn in tighter spaces than 40 ft trailers.


Just found that they have a Youtube channel and uploaded several videos about 10 years back...

Edit: Google images would appear to show that these went into production.