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minor power/tractive effort number discrepencies for modern locomotives.

Started by ӔO, August 25, 2010, 03:26:40 PM

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ӔO

some of the power numbers looked odd, so after taking a look at ever so reliable wiki, the following locomotives need correction. I skipped over the ones that were close enough to what's listed on wiki.

BR class 71, 2240kW, 195kN - should be: 1720kW, 195kN
BR class 73, 2350kW, 186kN - should be: 1059kW, 186kN
BR class 87, 5860kW, 258kN - should be: 3730kW, 258kN
BR class 90, 5860kW, 258kN - should be: 3730kW, 258kN

jamespetts

AEO,

thank you very much for the corrections, which will be applied in the next version. The incorrect figures were inherited from Simutrans-Standard, where often odd power numbers were used to compensate for the physics model. Your assistance is much appreciated!

ӔO

No problem.
I really wonder who put in all that info for BR locomotives. As unreliable as wiki is, this info looks like it's all spot on.

jamespetts

I think that some of these assets date from 2006; not entirely sure where the numbers come from.

kierongreen

The power figures should have been fairly accurate - they were sourced from a few websites. The gear value was then used to balance.

jamespetts

AEO - I think that your last reply to this topic was lost in the recent server move :-( Can you repost it?

ӔO

yes, it's the BR-class 52 'western'
It has gear multiplier enabled to 0.8, when it probably shouldn't.

jamespetts

AEO: That was intentional, as, as far as I understand it, the Class 52s had a design fault making the gear ratios all too tall, greatly impeding the class's acceleration. This seemed the most sensible way to simulate that (unless you have any better ideas...?).

ӔO

ahh, okay, I see.
if it has a gear problem, then perhaps the tractive effort could be lowered drastically?
currently it is set to 297kN, maybe something around 170~180kN will do, as I do notice that tractive effort does make a noticable difference in acceleration.

jamespetts

The difficulty with that is that it would involve using the non-realistic figure.

ӔO

then perhaps a combination of both lower tractive effort and gear?
I see the listed tractive effort in both continuous 201kN and maximum 297kN. some number between these two extremes, plus the use of the multiplier to mimic the effect of having trouble reaching top speed.

at 2025kW * 0.8, would make the engine 1620kW, 297kN. As it is supposed to be a mainline diesel to replace all the steam engines on the western lines, it wouldn't make much sense that it doesn't produce similar power to that of the 7MT brittania or GWR king class.

The current gear also makes the class 52 not much better than the Class 40 that is introduced in 1958, that has 1500kW, 231kN and the introduction of the class 47, 1922kN, 255kN, the following year, 1962, makes the class 52 very unattractive to use. I know it may not have been a popular engine, but it should at least offer an interesting choice for switching over to diesel.

actually, to that effect, class 47 is incredibly cheap to operate and needs to have a its maintenance increased. I'll start another thread about that.

kierongreen

It's worth keeping in mind that certain locomotives (in particular 37, 47 and 08 should be 'better' overall than others, after all they are now 50 years old and still in service...)

ӔO

Quote from: kierongreen on September 02, 2010, 03:48:16 PM
It's worth keeping in mind that certain locomotives (in particular 37, 47 and 08 should be 'better' overall than others, after all they are now 50 years old and still in service...)
yes, definitely.
It's just that in its current incarnation, it's not much better than a class 40 and not a good replacement for GWR king or BR 7MT, yet costs the same as a GWR king. holding out one year, to 62', for the class 47 is very much worth it, as the two steam engines are not retired until 63' and 68'

kierongreen

Well the early diesels were mostly unsuccessful, so to start with when they are introduced there should actually be little point in using them (imo). Electrics should start taking over on suburban services gradually from 1920's onwards but until the likes of 37, 47 and 55 come along there should be no huge reason to use diesel (unless you want to have the latest and greatest engine).

jamespetts

The maintenance cost of diesels should be dramatically lower than for steam - but that's for a future rebalance. The power of steam locomotives also need rebalancing, especially to calibrate them with Experimental's physics.