Class 60: 3100 hp
Class 66: 3300 hp
Class 70: 3700 hp
So a Class 60 is 'low' horsepower?
And don't go on about the top speed of a Class 60, you'll get differing opinions on here! lol
I take a locomotive at its at rail horsepower, the horsepower than it can actually use. As you'll know already a hell of a lot of power is lost between the engine and the rail. Thermal inefficiency is the biggest killer of horsepower. Then theres electrical resistance, mechanical friction between everymoving parts, innefficiency inherant in all internal combustion engines, transmission loss, alternator inefficiency and I'm sure alot of other contributing factors.
Im not sure about the Mirlees engine of a Class 60. But the burning of diesel fuel in A Paxman Valenta 12RP200L actually put out close to 4,474Kw/6000hp of energy, but 3,750hp is lost to thermal and machanical inefficiency before its even made available to the transmission giving an engine output of 2,250bhp and then, post transmission and ETH of course only 1,770arhp. Horses bolt quickly when the stable doors are left open.
A more accurate Idea would be.
Class 60: 2,415arhp, 60mph gearing
Class 59: 2,533arhp, 60mph or 75mph gearing.
Class 66: 3,000arhp, 65mph or 75mph gearing.
Class 70: Can't find the at rail horsepower. Anyone know?
Class 68: 3,300arhp. (I only added because of their superior haulage capacity vs a 75mph 66).
Class 67: 2,500arhp in freight mode and 2,100arhp in passenger mode thanks to ETH loss. (I though before that they only had 2,000arhp in passenger mode but after a little digging I stand corrected).
On paper a 66/6 should be the best, if it wasn't for the fact that they slip like mad and leave enough sand behind to top up Bridlington beach. Okay maybe a little exageration there, but when I was doing my P-Way maintenance training I was told about 66/6's dumping sand into S+C and jamming the switch blades.
If I was to rank them in order of haulage capacity i would do so as follows.
Lowest.
Class 67 (By a long way).
Class 66 standard.
Class 66/6.
Class 68.
Class 60.
Class 59/2.
Class 59/0 and Class 59/1.
Class 70.
Highest.
The above list is controversial and i'm sure i'm gunna get some stick for it. LOL.
Haha, Im sure that I would indeed get differing opinions on the top speed of a tug. Im sure there are some sneaky, gutsy, or just plane brilliant drivers that push them above their paper top speed. Naughty drivers. HEHE.
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HSTs manage the South Devon banks every day with no problem, same for the Highland Main Line. XC HSTs take on the Lickey (albeit with a good bit of speed first!) and they're not knackered. There's also some other decent banks on the XC routes, after all the climb out of Birmingham heading north goes up quite a bit. Can't remember the rest off the top of my head!
I'd say the HSTs will be having a bit of a relaxed retirement on the Inverness to Aberdeen route, compared to the hard work they're currently doing!
Perhaps is it easier then some of the climbs then get upto today but by 2021, they are gunna be 45 years old when they were only built as a stop gap.
Now as "Cosherb" knows

, I practicaly worship the HST but I think that by 2021 even the HST will be ready to go. I know there are plenty of much older locos still going strong but they were built like tanks to last years and years and years, were as the HST was only designed to be in service for a decade or so, before been dissplaced by the APT and other electrics. So they've already proved that they are capaple of doing far more then they are designed to do. I very much doubt they will be any good after 2021 unless Scotrail rebuild them again and give them another life extension, but thats highly unlikely as the cost would be massive and only give maybe another 5 years. Sadly nothing last forever.