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Blackpool trams underpowered

Started by Vladki, February 16, 2020, 04:11:27 PM

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Vladki

I noticed that the blackpool centenary is performing much worse than blackpool progress twin, although they have the same power. Then I noticed that the centenary is much heavier (20t vs 13t). Heavier than contemporary double deck trams (18 t). So I started to search if it was really that heavy. I found that according to https://orr.gov.uk/__data/assets/pdf_file/0019/1981/Report_FE-04-14b-part1.pdf (page 10), the weight was 17.5 t. I could not find any other source telling the weight. Also the source noted in dat files: http://www.britishtramsonline.co.uk/blackpoolfleet.doc has a bug in converting HP to kW. Centenary cars had 2x 57 HP engines, confirmed also here: http://blackpool-trams.yolasite.com/centenary-trams.php. But 57 HP = 42.5 kW, not 25 kW as written in the doc. This applies also for the Blackpool-EE-Railcoach, Blackpool-Brush and Blackpool-ProgressTwin-Power. Increasing the power would make it more useful with the trailer.

Also sources vary in the seating capacity of centenary trams: 52-54 seats + 16 standing.

Spenk009

I've amended the power values and added these in a new branch in case of integration, here.
The Blackpool Brush I've left at 60kW, as the wikipedia article mentioned in the dat file points to the Boat Car, which mentions 40hp engines. As to the capacity of the centenary, it's based on the document (blackpoolfleet.doc) for 52. The report talks of 55 seated and 20 standing, so I don't know what to recommend in this case.

I'd like to let James have a say on the topic. I'm not sure whether these trams are actually that underpowered.

jamespetts

Thank you very much for that research - that is most useful. I have now pulled Spenk's fixes.
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Vladki

#3
Looking at http://blackpool-trams.yolasite.com/, almost all trams had 2x 57 HP motors: balloon, brush, millenium, jubilee, twins, EE, centenary, OMO (EE upgrade) = 85 kW
Only boat trams had 2x 40 HP, but we do not have them in pakset. The comment is wrong.
Pantograph trams (1928): 2x 40 = 60 kW
And coronation 4x 45 HP ! = 134 kW: Soon after the Coronations began to enter service, the problems started. The trams suffered from fractured axles and also managed to trip section breakers in the Substations due to their high power consumption, leaving queues of immobile trams along the prom.
Standard trams: Motors: BTH B510 (no further specs) - but also looks underpowered in comparison with contemporary sheffield and glasgow standard trams.
Flexity: Motors: 163hp x4 = 486 kW

I'll prepare patches

EDIT: while fixing the power figures. Is there any easy relation between power and tractive force for these trams?
I'm just tempted to comment out the tractive force as these were probably totally guessed numbers, and completely invalid after the power has been changed.

Extrapolation from other trams Blackpools with 85 kW, same engine so also the same tractive force - guess at 48 kN
Coronation was extra strong 60 kN ?
Jubilee and Centenary are OMO - lower running costs

And I think that at least millenium should be available only as upgrade. Truly the only new trams since 1930's were coronation (1953) and centenary (in 1984), all the others were upgrades of balloon, brush or ee-railcoach. But otherwise there would be no new trams for many years.

https://github.com/vladki77/simutrans-pak128.britain/commit/f7cdf52aa3f669ec61511b401da8a83620b90e34

jamespetts

Thank you for this. I note that you have managed to find real tractive effort values for some modern trams, which are significantly lower than the guessed tractive effort of the much older Blackpool trams. This would suggest that the Blackpool trams' tractive effort needs to be reduced down rather than up.

As to the Millennium tram, I believe that this was available to purchase new because of the paucity of other trams available at the time, although I cannot immediately recall now the timeline details for this.

In any event, I have incorporated these changes now: thank you for your work on this.
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Vladki

Quote from: jamespetts on April 26, 2020, 12:33:15 PMThank you for this. I note that you have managed to find real tractive effort values for some modern trams, which are significantly lower than the guessed tractive effort of the much older Blackpool trams. This would suggest that the Blackpool trams' tractive effort needs to be reduced down rather than up.

Yes, but that would require investigation and reducing the tractive effort on other older trams too. Now I have pushed reduction from 48 -> 40 kN on most blackpool trams. So at least they do not exceed modern trams tractive effort after scaling by gear ;) Maybe further reduction down to 35 would be OK. At least they should be more powerful than Blackpool standard (35 kN). blackpool-coronation: 60 - reduced to 50, originall was 37, that feel too little compared to standard, with half power.

However there are other trams form 1900-1950 that are out of 30-40 kN range:
glasgow-standard-4: 52
lcc-e3: 25
lcc hr2: 64
sheffield-roberts: 42
Perhaps more investigation if the power (kW) figures are correct would be needed, knowing that there was a bug in HP to kW conversion on Blackpools.

Vladki

#6
Quote from: jamespetts on April 26, 2020, 12:33:15 PMAs to the Millennium tram, I believe that this was available to purchase new because of the paucity of other trams available at the time, although I cannot immediately recall now the timeline details for this.

Looking at the http://blackpool-trams.yolasite.com/

Blackpool double deckers:
Standard trams: 42 pieces, Built: 1923-1929  withdrawn 1940-1966, most of them 1950-1952, no upgrades.
Balloon trams: 27 pieces, Built: 1933 - 35  some still in service (B fleet and heritage fleet) after various overhauls.
Jubilee trams: 2 pieces, built 1979 and 1982 as major overhaul of balloons, change to one-man-operation, thyristor controller
Millenium trams: 4 pieces, buit 1998 - 2004 as overhaul of balloons, but not so much as jubilee, still 3-man-operation

Single deckers:
pantograph and boat trams: missing from pakset
EE railcoaches: 24 pieces, Built: 1933-34 (series1) and 1935 (Series 2), upgraded to OMO or twin, unmodified probably only in heritage service
Brush: 20 pieces, Built: 1937, not suitable for OMO rebuilds, most sold in 2010, now only heritage service
VAMBAC: 12 pieces, Built 1939, withdrawn 1962, not in pakset, no tech specs on that page
Coronation: 25 pieces, Built: 1952/53, withdrawn 1968-71, VAMBAC controller, too powerful for the electric infrastructure
Twin: 10 pieces, rebuilds of EE, 1960-62, regular use up to 2011, now in heritage fleet
OMO trams: 13 pieces, rebuilds of EE,  1972-76, withdrawn 1993, not in pakset,
Centenary: 8 pieces, Built: 1984-1988, withdrawal 6th November 2011.  NEW but same motros as EE, brush and balloons, only with thyristor controller like Jubilee,

EDIT:
on second thought I would mostly leave it as is, with the following changes:
- do not allow upgrade from jubilee to millenium, as it would be a downgrade (jubilee was more complex upgrade than millenium)
- allow millenium only as upgrade, there are modern trams available at that time

these, although not realistic could be kept:
- allow jubilee as new, it is technically similar to centenaries, which were available as new
- allow twins as new, as coronation trams were withdrawn quite early, and there would be a gap until centenaries.
- allow upgrade from brush to twin - although it did not happen in real world, brush and EE railcoaches were very similar so theoretically it could have happened.

I'll leave the final word to James in this regard.

Vladki

Further thoughts about Blackpool trams.

as noted before, blackpool trams since 1930's (Balloon, Brush & EE Railcoach) use the same engines (with exception for Coronation). So they should have the same power, tractive force and running costs. Maybe the modern controller in Centenary & Jubilee, could make a difference, but not so big as it is now: The original balloon, brush and railcoach are 34 c/km, twinset & millenium 17 c/km, junbilee & centenary 8 c/km. I think they should be united at 17 c/km. (And a conteporary glasgow-coronation also scaled to the same runnigcost/power ratio).

BTW Why is the runnigcost/power changing over time? Currently it is:
0.60 c/km/kW till 1918 (blackpool original, dreadnought toastrack)
0.40 c/km/kW 1923-1937 (blackpool standard, balloon, railcoach, brush)
0.20 c/km/kW 1948-1958 (blackpool coronation, twin, millenium)
0.10 c/km/kW 1979-now (blackpool jubilee, centenary, flexity)
I think that balloon, railcoach, brush, jubilee & centenary should be all in 0.20 group.

Jubilee & Centenary should have reduced monthly costs and increased loading time, as they are one man operated (i.e. without conductors). But looking at the fixed_costs, practically all trams are in range 6000-6600, including powered parts of articulated trams. So it seems that conductor wages have not been taken in account at all, or were considered only a few 100 cents. Even driver wages are at the moment at most 10% of monthly costs. That is IMHO wrong, but it should be balanced over all means of transport. So the question is - is there any standard for calculating crew wages in pak128.britain? 


Regarding the acceleration/tractive force, I see that most of the classic trams (pre 1990) are probably overrated. Maximum comfortable acceleration/decceleration is somewhere around 1.4 and even modern trams do not have higher acceleration than that. Also usually the tractive effort is usually not significantly higher than brake force, and there are practical limits to avoid wheelslip. In my calculation max_brake_force=weight*g*0.15, gives decceleration slightly above 1.4 m/s^2. So this could be taken as a safe value for further calculations.
All tractive efforts defined for trams older than 1990 are high above this value. E.g. for blackpool balloon, it should be 30 (or 24 after applying gear). For single deckers it would be only 20, but they have the same engine so tractive effrot should be same as well. And modern flexity 2 in blackpool has acceleration only 0.5 m/s^2... I doubt it is much slower than older trams. For that acceleration, balloon would need tractive effort only 11 kN (8.75 after gear). But this would require rebalancing all trams, otherwise blackpools will be at great disadvantage compared to others.

Does anyone have any source on real acceleration values of older trams?

Sirius

Quote from: Vladki on May 11, 2020, 08:30:53 PMSo they should have the same power, tractive force and running costs.
Not neccessarily, but likely, especially the power.
The force greatly depends on gearing, the power depends on further electrical parts like the transformer.

Quote from: Vladki on May 11, 2020, 08:30:53 PMAnd modern flexity 2 in blackpool has acceleration only 0.5 m/s^2
That 0.5 m/s² mentioned on wikipedia seems very small to me as a starting acceleration. Might be average acceleration to max speed or something like that.
I might dig deeper into this later.

Quote from: Vladki on May 11, 2020, 08:30:53 PMDoes anyone have any source on real acceleration values of older trams?
Sorry, but no. There is quite a lot of data about blackpools tram history but barely any technical data out there.

Ranran(Hibernating)

#9
I have previously proposed in another thread, but I think the driver costs should be separated. The tram may also connect two trams. (Well, there are few examples on trams, but there are many with trains). In that case, one tram driver is not needed. This doesn't always pay off. You pay for equipment and maintenance costs for cab equipment, wasted vehicle space, and vehicle weight. These elements are important in the recombination system and also increase the game's strategy and more realistic.


QuoteNot neccessarily, but likely, especially the power.
The force greatly depends on gearing, the power depends on further electrical parts like the transformer.
That's right. Gear ratio is also relevant. A high gear ratio means that the distance traveled during one rotation of the motor is short. Instead, you get a high momentum.
That is, the power consumption per distance is high.
It is preferred when carrying heavy objects or when you want high acceleration, but it is not suitable for running many distances at high speed.

If you rely solely on KW, you need to look at how long it has been up. When accelerating slowly, the motor is loaded for a long time. Even if the maximum speed is high, it continues to consume power for a long time.
Well, coasting can be energy efficient, but it's not practical because you need to simulate power consumption to think about it.
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Sirius

#10
Quote from: Ranran on May 12, 2020, 12:31:36 AMWell, there are few examples on trams
Actually not that few ;)
In the pak there are currently 4 such trams.
Btw. why does a sheffield tram driver earn 1.20 per month, whilst a T68 driver earns 1.66 and a T68A driver earns 1.44 and a flexity swift driver earns 1.22?
Seems like the trade union in Manchester did a quite bad job disputing decreases in loan, where they should rather dispute increases!
Trade union in sheffield seems to be completely incompetent.
Their tram conductors are paid worst, where at least tram-train conductors likely need advanced training to operate on both, the tram sections and the railway line.

Vladki

First have to at find out how much of the monthly costs is the real maintenance of the vehicle, and how much are the staff wages. Even if it would be all summed into one figure, we have to know the raw figures. Then we can do stuff with them and implement some complex way of separating driver wages from maintenance to properly simulate trains with multiple working - more cabs than drivers, etc...

Blackpool trams had also the same bogies, so we may safely assume that the gearing was the same too. Only Jubilee and Centenary had thyristor controller, while the others rheostatic, so this could add some bonus (most probably in running costs).

The difference in T68/68A/flexity is not in wages but in reliability. Drivers get 1.00 ;)

Sirius

If so, why is the front cab more expensive (less reliable?) than the rear cab?
Anyway, I wouldn't take too much care of loan yet if it is planned to seperate these costs later on.

Vladki

Quote from: Freahk on May 12, 2020, 04:46:48 PMIf so, why is the front cab more expensive (less reliable?) than the rear cab?
good point ;) As said before, balancing this correctly is huge task, and I'm not going to do that. I'm focusing on technical data.