From pictures I've seen, the shape as viewed from the front is identical to the Shenfield electrics but they were 3-car sets of open plan coaches with a combination of transverse and side facing seats and air operated sliding doors.
If you looked, you could see there the original 1,500V pantograph had been after they were converted to 6.25kV/25kV operation - Liverpool Street station and the lines out of it through heavily built up areas was operated at 6.25kV whilst the country areas were 25kV.
Dual voltage trains are no longer required as the entire line is now 25kV - it always amazes me to see how little clearance there is on many underbridges and at Liverpool Street itself where the fresh air under the station canopy was sold off during redevelopment and a concrete raft supporting a shopping area now sits across the tracks!
(17-04-2017, 10:08 AM)Refugee Wrote: [ -> ]What voltage do these modern trams run on?
The ones in Nottingham run on 750 volts DC IIRC, we had a little booklet come in2003 that told you all about when it fired up. They make a very strange whining noise when slowing down or on over run going down hill..
Nottingham trams do indeed run on 750V DC.
I would guess that the whining noise is caused by regenerative braking.
Croydon Tramlink, 750dc, with substations taking 6.25 or 11kv att 600 to 1000kw, transforming it down and rectifying it.
I must admit, havng been Stateside a few times, I was unimpressed by the use of 110vac supplies and their blaise attitude to it.
You walk into a bathroom. No pull cord, just a standard light switch inside the door. The sink has a power socket next to it for your hair drier, if they could get away with a socket in the shower they would. The small kettle (and it is small) that is often supplied is of the lowest wattage it can be to boil water without cooking the power outlet. The same applies if you get an ironing board and iron, the lowest they can get away with. The plugs themselves are a bit of a joke with no slieved pins and the earth often an optional extra. it's all very much a bygone age when it comes to standards. Cabling is often double the thickness when compared to our standards but for a basic table lamps it's not unusual to find the cable from the power point to the lamp itself is warm to the touch.
Outside, not much better. In major cities it's all buried but get outside into the burbs and power posts abound with local transformers on posts, along with the odd juiced squirrel that got unlucky when jumping the excuse for an insulator. A cooked racoon or brown bear is not unusual either.
We are lucky in this country, we have a supergrid. The US system is still stuck back in the 50s and is often creaking at the seams.
No, I think our adoption of 240vac is an inspired choice, and our supergrid even more so.
A couple of examples how our standards are better.
That's not the same Vitali Vitaliev who used to regularly appear with Clive James on television, is it?
If a hypothetical Country that had never had electricity decided to electrify, what voltage would they choose? If i was in charge I'd be pragmatic & choose 230 volts AC. However if I wanted to protect my fledgling electric gubbins manufacturing industry I'd choose 180 volts DC. I'm surprised France didn't choose that voltage with their history of 819 lines, positive modulation/AM sound 625 lines, SECAM colour & yellow headlights, lol...