Sprinters came with obvious economies......or did they?
Firstly you are comparing a completely new capital investment with refurbishment of stock and locos, which actually happened anyway, but in the early 80s fixing stuff was still cheaper than buying it new (from China as is now)
Secondly, while on the comparison, there was an ageing fleet of locos.....well a lot of poorly made 6LDA mass produced locos which were underpowered. Also there were many non standard classes of this inferior power around. Take 37s and in particular refurbished 37/4s out of this equaiton and the economic comparison gets a lot better.
Then there is flexibility of capacity: a sprinter allegedly increases seating: but take 9 seats away from 163 as billed, which makes 76 per coach versus 56 in a mark I: but the mark one has more luggage room , and more toilets. A sprinter you have a large capital asset lying about if you lay up stock outside peak periods because motive power is "integral" and they are quite expensive. Mark I's were all built with public money and along with mark IIs lasted actually to 2010 in public service. So were sprinters, and then sold off at a rate which is difficult to calculate.
In other words you can leave a coach or rake of coaches lying around or make up and break up sets for what ever reason at a far lower "loss overhead" and then you can mothball or sell them as a private company. So a sprinter will be say load 4 a notional 300 seats, seemingly you need load six to cover this. But with load 5 and a brake and parcels van you can carry more bikes, luggage, sea food on ice etc.
Now if a loco fails you may have on hand one loco spare to cover several trains at a given reliability ( miles per casualty, local allocation class availability, number of loco hauled trains, risk of failure in service, average time to mid route, hours per day...so on so on a big nasty calculation and algorythm)
When a sprinter fails then there is no loco to swap and you need a loco or usually now a nother sprinter to pick it up.
The lack of flexibility is the crux on this. WhileA 37 on load 2 still probably pops out 1000hp and not 560 odd, while on load 8 or 9 as in the usual summer trains to Oban and Ft Bill and load 10 to Inverness often, then a 37 produces 1750hp : you would then be doing the same as 1716hp in three sprinters lined up.
Also each coach then has 286 horse power and a 75mph top speed ( okay 37/4s top out about 75-80) so load 4 has 4 engines and a little over a thousand hourse power. But when Ideling you have four engines at a higher RPM than a single v12 mid engine sitting at 400rpm.
So I have set out on my own little debate with yours truly, and on fuel and absolute seating capacity a 37 on load 5 fails. But on flexibility, reliability relative to cancellation and getting stuck somewhere for a very long time.ha
Lastly though in this rant, sprinters were trialled and despite having eventually the same hp on load 6 as a 37 on 8 , they still needed 20 minutes to 30 minutes longer . Slower in fact as the type 2s which could if thrashed to death and failure, could keep up with the 37 diagrams on load 3 at least. Those diagrams having actually a good percentage of slack with 37s coming in early to GSQst or meeting signals at Singer especially for getting ahead of themselves at 80mph! A 37 on ETHEL ( 350 tonnes nett haul) made up 40 nminutes between Crianlarich and Dumbarton ( see other blog on 37014 and Peter Walker). The outgoing timetable for 37s had 40minutes added Dumbarton- Glasgow to make the new sprinter time table look quicker! Of course the actual diagram was business as usual and the syphons probably delighted Ada and Bert by being in so darn early!!!
I did about 15,000 miles off 37s, mainly boilered ED ones and mainly on the WHL. 35mph average. I had maybe one fail on me underway and a few failures causing delays, also probably there were a few more failures prior to dropping on the train wheere another loco had to stand in. After rail faires went up so much, I was skint once and coming from Edinbra to Oban and saw that the bus went via Calendar and was therefore shorter and faster. It was ok the bus. Then I did via Inveraray and it was kind of a better route if not just for the novelty. It was cheaper and just about as quick as a plastic sprinter and on the more modern busses with a shitter and good suspension and sound proofing, it was actually more comfortable than doing plastic up the WHL.
So sprinters were slower and more cramped than mrk Is with a syphon G on the front, but saved maybe on fuel, and some degree of modernity and standard parts. Virgin have the figures on running the modernised class 37/4s on mrk IIs in comparison to their units and data on sprinters is probabkly about. They key thing is that you can't do load one or load 10 effectivly with a sprinter; They are notably slower; for a 37/6 or /0 then they cannot go as fast ( 105mph trail on the Edinburgh-Glasgow route ) There is less space for baggage and bikes; the windows do not all align with seating; there are fewer toilets;They cannot work freights or recover other types trains in the way in front of them; neother can they sod off for a bit of overtime on the night shift and do freights and PWAY trains at night There is relatively less space for getting on and off, although the doors are wider; they use more fuel on idling due to the higher speed engine and the local demand for electricity; But the real show stopper for sprinters - if one fails then you have to put people on a bus, and if one is not available then you mess up your whole day. They lack substitutability. A fail is a major fail, possibly for a six car train.
For us of course, there was no thrash and no getting away from the bright lights and wedged in masses. No sticking your head out the windaes. No dossing in an empty Comp'o. Frankly on most routes they cover now I would rather take the bus and on the 170/ 1xx /2xx routes it is often cheaper and quicker for a family of four to hire a focus sized car. Micky and Mousey Air are cheaper and a lot quicker in most of the dildolino routes, and the ECML is tethered back to 125mph anyway. So I avoid the big railway now : it is a plasticy brave new world, but with enough ghosts from a glorious past of public ownership with blue sides and yellow ends.