Can Maglev run at full speed while climbing a slope?

[bigbullking]

In OpenTTD, Maglev train will slow down while climbing a slope. Indeed in real life, train must be like this, but I really like to see a Maglev train always run at full speed. I remember there is such an option in TTDPatch. Is that possible in OpenTTD?

[Ailure]

Yes, turn on "realistic acceleration" in the configure patches window.

[bigbullking]

turn "realistic acceleration" on
------> Meglev will slow down while climbing slope; turning a corner; entering a station

turn "realistic acceleration" off
------> Meglev will slow down while climbing slope

Meglev train still cannot run at full speed while climbing slope.
Any other solvent?

[DaleStan]

MiniIN may have something satisfactory, but it is in planned obsolescence.
Failing that, use TTDPatch.

[Ailure]

Meglev train still cannot run at full speed while climbing slope.
Any other solvent?

Yes they can, just don't make it a too steep slope and it should work fine.

Also didn't you notice that the slowdown is less with realistic acceleration on? >_>

[XeryusTC]

turn "realistic acceleration" on
------> Meglev will slow down while climbing slope; turning a corner; entering a station

The realistic acceleration model needs wider turns to keep trains up to speed. And trains need to slow down when entering a station, how could passengers (savely) get on or off a train if it is traveling at 500km/h?

[sc79]

turn "realistic acceleration" on
------> Meglev will slow down while climbing slope; turning a corner; entering a station

turn "realistic acceleration" off
------> Meglev will slow down while climbing slope

We've been here in threads before, and the conclusion from those that matter was that, although people seem to turn realistic acceleration off purely because they want a game where trains run at full speed all the time, somehow them dropping to ~20% speed on single square hills is considered working as it should.

Put simply, theres no way to do what you want.

[Dave]

turn "realistic acceleration" on
------> Meglev will slow down while climbing slope; turning a corner; entering a station

The realistic acceleration model needs wider turns to keep trains up to speed. And trains need to slow down when entering a station, how could passengers (savely) get on or off a train if it is traveling at 500km/h?

I've never been in a station where I get on a train that's still moving...

[hertogjan]

We've been here in threads before, and the conclusion from those that matter was that, although people seem to turn realistic acceleration off purely because they want a game where trains run at full speed all the time, somehow them dropping to ~20% speed on single square hills is considered working as it should.

Put simply, theres no way to do what you want.

Using a realistic acceleration patch surely helps. You can use the one in MiniIN, or use the physics patch* with the trunk (of which the newer versions are more configurable** than the one in MiniIN) - if you know how to patch and compile.

*Search for the topic in the OpenTTD Development section of the forum.
**That allows you to set hill gradient to 0, which essentially ignores hills concerning road vehicle and train speeds. Also, the maximum curve speed can be set can be set as high as possible, so that curves have minimal impact on train speed. But it still won't allow you to have maglev trains traveling 1600 km/h through the tightest curves, however.

[Mchl]

Being at that topic.

Does anybody know, how good maglevs are in coping with slopes in reality?

[V]

Well, I didn't work with them or so, but what I can say:

Maglev is propelled by magnetic force, which limits are pretty much constant, hardly depending on speed. Meaning, it has problems accelerating, in general.
On hills/slopes, the train has to either apply extra force or trade speed for height. Since the extra force is already spent keeping it from touching the track, we can assume it is, at best, constant.

If so, the speed drop will be ruled by equation:
mv1^2/2-mv2^2/2=mgh, where v is in m/s, h is in meters, g is gravity.
Simplified, it is v1^2-v2^2=2gh. Assiming the speed drop is not too high, v1^2-v2^2 can be approximated as 2*v1*(v1-v2), or 2*v1*deltaV.
So, as 2*v1*deltaV=2h*g, we can find the approximate deltaV as 10*h/v1. This is underestimated somewhat, but not much for low deltaV. At high deltaV it would be double that figure, so correct can be interpolated.

But, generally, a train at speed, say, 100m/s (360 km/h) will lose at slope of 10m just 10*10/100=1m/s, and at 100m just 10m/s (12m/s with correction). Theoretically, by itself, the train's own speed could lift it to 500m.
And, the higher the initial speed, the lower the speed loss. At 200m/s it would be just half that.

So the rest depends on the suspension system, on how hard is it to keep the train in the air, applying local strong force.
It seems to me that normal trains must be much better in dealing with slopes: not only they have more torque at low speed, but their track contact provides increased force by itself, without extra effort. However, if all problems are solved, the only reason for fast trains to climb slowly is safety. Unless the slope requires energy comparable to their kinetic energy, in which case only engine power determines the climbing speed.

[Mchl]

It seems to me that normal trains must be much better in dealing with slopes: not only they have more torque at low speed, but their track contact provides increased force by itself, without extra effort.

So it seems to me based on my somewhat vague idea how maglevs work (ok, maybe not so vague, I'm doing my engineereing degree this year, but not in public transport )
It also seems to me, that it maybe quite a trick to keep a maglev train in place (i.e. waiting before signal) on a sloped track. Unless you let it lie down on its track of course

[hertogjan]

It also seems to me, that it maybe quite a trick to keep a maglev train in place (i.e. waiting before signal) on a sloped track. Unless you let it lie down on its track of course

That would be a hypothetical situation, since maglevs don't have to wait for signals, since there aren't any; the movement of the train is controlled by the track, not by the train itself. Computers which control the track magnets will make sure that trains do not collide (not with eachother, at least).
I don't see any obstructions to maglev-tracks being inclined. One could construct a heavier track where more power is needed, without adding extra weight to the trains. This is impossible for conventional trains (i.e. vehicles which have their power source on-board), since more power would need more powerful engine, but if the engine is also heavier, so one needs even more power, etc.

[WWW]

I've never been in a station where I get on a train that's still moving...

am I the only person who exploits these MGR coal trains?

[Firestar]

on how it works you will find a bit about how they work, also what country's are currently using them, and what they are able to do

[DudeWheresMyTank]

turn "realistic acceleration" on
------> Meglev will slow down while climbing slope; turning a corner; entering a station

The realistic acceleration model needs wider turns to keep trains up to speed. And trains need to slow down when entering a station, how could passengers (savely) get on or off a train if it is traveling at 500km/h?

I've never been in a station where I get on a train that's still moving...

that's because you always opt to pay the fare...
if you want to stowaway as a boxcar driter, you run along side until you see an opening and you throw your vagrant sack on there before you hop on

[csuke]

It seems to me that normal trains must be much better in dealing with slopes: not only they have more torque at low speed, but their track contact provides increased force by itself, without extra effort.

So it seems to me based on my somewhat vague idea how maglevs work (ok, maybe not so vague, I'm doing my engineereing degree this year, but not in public transport )
It also seems to me, that it maybe quite a trick to keep a maglev train in place (i.e. waiting before signal) on a sloped track. Unless you let it lie down on its track of course

that is what happens, it is only at a certain speed that maglev's stop using their wheels and "fly"
hence it is quite acceptable to have maglevs stopped on slopes in-game, assuming we are allowing them to go up slopes at all

[init]

that is what happens, it is only at a certain speed that maglev's stop using their wheels and "fly"

I think you are at least partially wrong. From http://en.wikipedia.org/wiki/Maglev_tra ... nal_trains

The German Transrapid, Japanese HSST (Linimo), and Korean Rotem EMS maglevs levitate at a standstill, with electricity extracted from guideway using power rails for the latter two, and wirelessly for Transrapid. If guideway power is lost on the move, the Transrapid is still able to generate levitation down to 10 km/h speed, using the power from onboard batteries. This is not the case with the HSST and Rotem systems.

[init]

It seems to me that normal trains must be much better in dealing with slopes

The Transrapid website argues that you are wrong, and that it is much more suitable for mountaineous regions than ordinary trains. It is a marketing website though, so claims should be taken with a grain of salt.

Anyway, the slowdown on slopes in OpenTTD is far greater than in the real world, since in the real world train tracks are built with extremely long and gentle grades. No real train slows down to a crawl just to go up a hill, but then the slope is much more gentle than in OpenTTD, although I understand that this is an engine limitation of the software. I do think that slowdowns should be heavily reduced for all trains, at least on one-tile slopes (you simply can't build a gentler slope than that).

[sc79]

Anyway, the slowdown on slopes in OpenTTD is far greater than in the real world, since in the real world train tracks are built with extremely long and gentle grades. No real train slows down to a crawl just to go up a hill, but then the slope is much more gentle than in OpenTTD, although I understand that this is an engine limitation of the software. I do think that slowdowns should be heavily reduced for all trains, at least on one-tile slopes (you simply can't build a gentler slope than that).

Except that the issue isnt with realistic acceleration on. When its on, trains slow down on corners, hills, stations, and generally behave (not surprisingly) realisticly.

However, with realistic acceleration off, trains run at (or as close to as possible) max speed on corners, stations, depots (iirc) etc, but slow to almost a stop on single tile hills, which seems at odds to every other aspect of the setting, and makes the option pretty much unplayable.