This patch aims to change all of this. As of version 2.0, it works for all types of vehicles. The patch has the following features:
- Different types of breakdowns. Not all breakdowns are the same. Road vehicles, trains and ships suffer from these types of breakdowns:
- Mechanical failure: The classic breakdown with black smoke. 10% chance. (Renamed from Critical to Mechanical failure, on YukonRob's suggestion. Thanks!)
- Emergency stop: Someone pulled the emergency brakes. The train comes to a full stop, but it can quickly continue. This only happens to the front engine, with a 10% chance.
- Lower maximum speed. As the name implies, the maximum speed is lowered. The lower the reliability, the lower the speed limit will be, although this is partially randomized. 30% chance.
- Reduction in power. There is a 25% chance that power will be reduced by a percentage (10-90%, reliability-dependant) and a 25% chance that it is reduced to zero. Braking is unaffected. The effect is that the train simply has less HP than normal, or even no HP at all. Therefore trains accelerate more slowly or they even decelerate. A stopped train with 0% power won't move at all until the breakdown is over. Trains will not roll backwards down hills, though, as train drivers are smart enough to apply their brakes to avoid that
(total chance: 50%)
For aircraft the breakdowns are different. They have 3 types:- Reduction in speed, similar to the old breakdown but with a variable speed limit. 70% chance.
- Forced service at the next airport. If the next airport does not have a hangar, go to the closest airport which has one. (20% chance)
- 10% chance for an emergency landing, but only when the reliability is less than ~87%. In this case, the aircraft goes to the nearest airport (actually the nearest hangar) and attempts an emergency landing. There is a 2% chance that the aircraft will crash. To compensate, regular crash chance is decreased from 0,07% to 0,01%.
- Full multiengine support for trains. Every engine in the consist can break down. This has some consequences for the GUI: The train details window now shows the average reliability and total number of breakdowns since last service. Per-engine information can be found in the information tab. (See picture below)
- A rework of the original 'when to break down' algorithm. This means better randomization and a slightly reduced breakdown chance. This is shared by all vehicle types However, because breakdowns are no longer by definition a complete stop, their effects upon a (train) network are significantly reduced.
- For trains, breakdown chance now depends on the load. An engine pulling a single car will break down less often than the same engine pulling a dozen cars. The breakdown chance of an aircraft is somewhat dependant on their maximum speed. To compensate for the fact that faster planes spend less time in the air, faster planes are more prone to breakdowns.
Tick the box "Enable improved breakdowns" in the vehicles tab of Advanced settings. Realistic acceleration is no longer necessary, but recommended nonetheless.(Dev Note: Some parts, such as the breakdown chance algorithm and the GUI changes, cannot be switched off)
If anyone has a suggestion, bug report or anything else to say, please post. Since a patch like this can quite an impact on gameplay, feedback is very much appreciated.
Changelog
V1.1
- Fix: If without power, a train would not decelerate below 3 km/h.
- Fix: Trains would not break down at all with realistic acceleration disabled, if it had not been enabled before.
- Renamed 'Critical failure' to 'Mechanical failure' (Thanks, YukonRob! Me likes it

- Clarified some stuff in the forum post. (in italic)
V2.0
- Feature: Support for all vehicle types.
- Feature: Realistic acceleration is no longer required
- Fix: Scrolling in the Information tab of the train details window did not work correctly.
- Other miscellaneous fixes and code changes
- Updated forum post to reflect all changes
V2.1
- Change: Non-front engines no longer have emergency stops. This should alleviate the problem of multiengine trains stopping too often somewhat.
- Fix: Reliability decreases for all train engines even if improved breakdowns are off.
V2.2
- Fix: Compatibility with previous versions was broken, causing stalled aircraft and incorrect breakdown chances.
V2.3
- Feature: Multiengine trains now have a reduced breakdown chance, depending on the number of engines
- Complete code check, resulting in many small improvements, changes and fixes.
- Win32 binary is now supplied. I used Tekky's language.patch, many thanks to him. (language updates are not included in the patch file itself, though)
V2.4
- Several small fixes by sbr (see flyspray)
- Fixed several minor issues, mostly regarding the behaviour when this patch is switched off.
EDIT: Flyspray task: http://bugs.openttd.org/task/2302
See this post for language.patch: http://www.tt-forums.net/viewtopic.php? ... 45#p741445