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Author Topic: Question on some locomotives  (Read 3945 times)

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Offline wing044

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Question on some locomotives
« on: November 15, 2009, 05:59:33 AM »
Hello. I have some problems with pakBritain locos.

SR Q1, top speed of loco is 120kph, but tender has top speed of 96 kph only.

BR Class 35 and 47, very low purchasing costs.

BR Class 47, top speed is 153 kph. Checking with Wikipedia the top speed of class should be 75/100 mph or 121/160 kph.

I checked the forum, but found nothing on these issues. (Or did I missed it?)

Offline The Hood

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Re: Question on some locomotives
« Reply #1 on: November 15, 2009, 11:19:07 AM »
Thanks for the reports.

As for costs, this is a known issue for all vehicles in the set - they are not balanced.  Work is ongoing to get this right, but it's not straightforward!

As for speeds those locos were both done by kierongreen a long time ago, and he did the research for the speeds.  I assume he had his reasons for that, and I assumed they were correct.  153kph isn't far off 160kph after all...  As for the Q1, does anyone know the true top speed of the loco in service?

Offline prissi

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Re: Question on some locomotives
« Reply #2 on: November 16, 2009, 09:43:34 AM »
There is no true top speed in service. Usually engine have a "top speed" which they are allowed to pass by 10% (or 20%) in case of catching up a schedule. If the Q1 could do secondary passengers, I think it would be able to rech 100kph. With only three axles much faster seems unlikely.

Offline wing044

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Re: Question on some locomotives
« Reply #3 on: November 16, 2009, 11:06:48 AM »
I've read a bit more about some locos on Wikipedia. I believe kieron has used the top speed of Class 57 for Class 47. Wikipedia page on Class 57 states top speed as 95mph/153kph.

Conveting 95mph to 153kph is not consistant with a few other locos. In the pak set, LMS Class 7P, BR Standard Class 7MT and BR Class 40 all appear as 155kph, which I suppose means 95mph.

In addition, from Wikipedia it seems that top speed of Class 40 should be 90mph. This should convert to 145kph, not 155kph at present.


Offline The Hood

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Re: Question on some locomotives
« Reply #4 on: November 16, 2009, 11:23:03 AM »
@wing044 - thanks for pointing these out.  The main problem is that actual data is missing for many locos, so data has been estimated, usually to the nearest 5kmh (e.g. 155kmh).  Others have been converted from mph presumably, hence 153kmh. 

I think there does need to be some tweaking of top speeds, especially in the steam era, as the top speeds in the dat file do correspond to approximate "top speeds" of the loco, but not the top speed usually allowed in practice.  This means when diesels appear, there may even be a drop in speeds, which isn;t actually what happened, as diesels generally operated at higher average speeds...

Offline kierongreen

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Re: Question on some locomotives
« Reply #5 on: November 18, 2009, 10:54:16 PM »
Also at different times the same class of loco may have had different set top speeds. I think this should be used to help differentiate between different classes of locos more when appropriate. So if a class 47 can be said to only travel at 95mph that differentiates it from a class 55 which can go at 100mph (for example don't take those value literally! it's been ages since I did the research but all units I added were researched in terms of power, weight, maximum speed, into dates and capacity). mph to km/h values should be rounded to nearest 5km/h but again some flexibility can be used when rounding up/down to give a range of speeds in game.

If you go on record speeds you get silly speeds - intercity 125 record is 148mph for example.

Offline jamespetts gb

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Re: Question on some locomotives
« Reply #6 on: November 23, 2009, 11:39:41 PM »
The top speed of most class 47s for most of their life was 95mph - the current datum is correct. There were some rare examples of class 47s with a maximum speed of either 100mph or 75mph, but 95mph was the norm for most of the class.

Offline wing044

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Re: Question on some locomotives
« Reply #7 on: November 24, 2009, 03:21:01 AM »
Thank you all for the replies. I understand you guys have a difficult task balancing the vehicles in the pak. I fully appreciate what you are doing.

@The Hood  -  I think tweaking of steam locos is very necessary. I read somewhere that steam locos were rarely scheduled for 100mph+ running. So the current speeds in the pak for some steam locos may not reflect their actual service speeds, but speed record attempts. Also the high speed of steam locos makes transition to diesel unprofitable, e.g. LNER A4 -> BR Class 55 results in lower profits.

@kierongreen  -  I did not realise the speeds are rounded to 5km/h until you mentioned it. I think this explains why I felt 153km/h strange.

@jamespetts  -  Looks like there's some misinformation on Wikipedia. Oh, how many times I'm told not to rely on Wikipedia and still I keep making the same mistake!

Offline jamespetts gb

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Re: Question on some locomotives
« Reply #8 on: November 24, 2009, 08:40:12 AM »
Thank you all for the replies. I understand you guys have a difficult task balancing the vehicles in the pak. I fully appreciate what you are doing.

@The Hood  -  I think tweaking of steam locos is very necessary. I read somewhere that steam locos were rarely scheduled for 100mph+ running. So the current speeds in the pak for some steam locos may not reflect their actual service speeds, but speed record attempts. Also the high speed of steam locos makes transition to diesel unprofitable, e.g. LNER A4 -> BR Class 55 results in lower profits.

To some extent, these issues are solved, or are in the process of being solved, in Simutrans-Experimental. In Simutrans-Experimental, a new physics engine is in progress (thanks to Bernd Gabriel - it should be in the next version out), and profits are based on the actual average speed of convoys or lines, not their theoretical maximum speed. Given that diesel locomotives have different power characteristics to steam locomotives, the latter of which accelerate faster, the overall result should be that switching from the A4 to the Deltic should increase, not decrease, profits.