New version released: Version 0.20
Link: http://goo.gl/1PzpZK

Changelog:

• Added AI controlled aircraft to the game. The aircraft are based in major cities and will patrol their nation's airspace and territorial waters - they are equipped with anti-shipping missiles and will fire them at your submarine if you are spotted.
• Added air search radar to the player submarine - this can detect air contacts up to 80 nautical miles away. It is controlled in the same way as the surface search radar.
• Added 10 new ship types. They aren't simply "Destroyers" or "Frigates" any more, there are now "Charles F. Adams Class Destroyers", "Sverdlov Class Cruisers" etc. All ships are equipped with historical armaments, and are used in the game only by the nations which actually used them in the mid-late 20th century.
• Added the ability to repair and rearm at friendly ports. Approach the port (can't be more than 1 square away) and press LShift+R - your submarine will be immediately repaired, rearmed, radiation will be removed etc.
• Added a new mission type: reconnaissance. You will be tasked to infiltrate a hostile port and observe enemy activities in the area.
• Improved hit detection; it is slightly more difficult to hit hostile ships, but your sub will also be hit less often.
• Minor graphical improvements.
• The "constantly exploding diesel engine" bug has been fixed! Several changes have also been made to the behaviour of other components when damaged. Now the damage models should be working correctly - generators, turbines etc can explode if they're being run while severely damaged, but if you turn them off you can safely conduct repairs. Similarly, radiation leaks from the reactors more slowly if they are shut down.
• Other bugfixes, mostly relating to the way missions are assigned.

Enjoy!

If there are any ship classes, cities or countries you want added to the game, don't hesitate to ask! It's quick and easy to add them.

Hi geoff, the latest update is awesome! I don't know if I've just missed it but is there any bilge pump facility to pump out flood water yet? What do you think would be a suitable max depth for the pumps to work before the outside water pressure is too great for the pumps to get water out of the boat? I'm thinking maybe 50 - 60 metres, this way there can be a race against time to get the water out before the weight drags you too deep.

No, work on the pumps took longer than expected (and required a bunch of other things to be changed) so I decided not to include them in 0.20, they'll be in the next version. Because of limits with the old file system, adding the pumps as new objects required me to redesign the entire submarine - so now I've completely overhauled how the game handles submarine data files to make building and editing submarines an easier and quicker process in future. Which was definitely worthwhile, as it simplifies a lot of other tasks too.

But back to the pumps. Previously I tried adding them in a similar way to the ventilation system (so they simply removed water at a constant rate from every room) but it was very difficult to balance - sometimes the pumps were almost useless, other times they were so effective it almost felt like cheating. Now, I've added them as independent objects in the game (like the diesel engines for example) so they can be individually damaged, destroyed, repaired etc. I hadn't considered the effects of water pressure but that's an excellent point, and provides a very good way to balance the system. At the moment I think the pumps should run at full efficiency down to about 30m, then taper off until about 100m where they will basically stop working - but this will require some testing and balancing. As you said, it should be a tense race against time! The pumps will definitely be included in the next version, and I expect the sonar system to be mostly finished by then too.

You are too cool for school!:rock:

I'm really enjoying this sim, great job.

This may sound a little odd, but is there any chance you could add a pause button? It's really frustrating when things are just getting exciting and the doorbell rings or the phone goes, if you're not careful you've got a smoking ruin rather than a sub!

Pressing 'esc' does the trick, press enter to resume!:up:

So it does, that'll teach me to rtfm!

Cheers

Would it be possible to add the ability for the crew to work on repairing the outer hull/dive planes when surfaced (obviously going outside the boat to do so).

Hmm, it's possible. Not sure exactly how that would work but I could try adding some way to open the hatch and allow crew to walk outside... I'll do some experimenting and see what works. In the meantime, remember you can be fully repaired at friendly ports by getting close and pressing Left Shift + R.

Hmm, it's possible. Not sure exactly how that would work but I could try adding some way to open the hatch and allow crew to walk outside... I'll do some experimenting and see what works. In the meantime, remember you can be fully repaired at friendly ports by getting close and pressing Left Shift + R.

Keep up the good work : )

Will do :salute:

By the way everyone, I don't think I've mentioned it before but (because of the way the crew experience/skills system works) it's possible to 'train' crew so they're better prepared for a disaster. Find an empty, unimportant area of the sub with nothing explosive nearby and use Tab to start fires or Left Ctrl to damage walls/floors/objects, then order the crew to extinguish the fires and repair everything. The crewmen will become more proficient at skills they practice regularly, so when a real emergency occurs they will be able to deal with it more quickly and efficiently.

This is a similar process to the training drills run on real submarines to keep the crew disciplined and well-prepared. I doubt they actually set real nuclear submarines on fire just to keep the crew on their toes but it's the same principle!

Just out of curiosity, would it be possible to make this game touch screen compatible, so I can play it with the stylus on my Win 8.1 tab?:hmmm:

edit: I have trouble shutting down both reactors and pumps, then restarting from cold without various things breaking. The worst is a loss of coolant, which causes an irreversable temperature rise and meltdown. Should equipment be this fragile?

Also, I've tried shutting down the reactors and running on the diesels with all vents open and the system purging, but the genny room O2 level still diminishes. Could the inclusion of a snorkel help with this?

Making it playable on a tablet would be very tricky - there are so many keyboard commands it'd be difficult to completely replace it with on screen controls. But I plan to expand the mouse functionality soon (so you can click switches, buttons etc) so I'll see how I go with the touch screen stuff then, if it doesn't seem too hard then you might be in luck.

Shutting down and restarting the reactors should be pretty safe... only thing to watch out for is running the pumps too fast, which can cause damage to them. Also make sure the pumps are running at full speed before you start raising the control rods. But I can't think of anything which would cause the components to start breaking - maybe it was just random failures which happened to affect the reactor? Increasing sub_reliability in gameoptions.ini should improve that if failures are happening too often. I'll look into it though - there's always the possibility of a bug sneaking in and causing failures to happen too often.

Loss of coolant is pretty deadly though, at the moment the only way to fix it is to return to port. I have an idea for fixing this which I will add to the next version. After all, the coolant is just water so there's no reason it couldn't be replaced while the sub is underway.

And thanks for letting me know about the diesel engine problem, I'll tweak the rates for the engine air consumption and ventilation system to fix that. Or maybe add a snorkel, but I think the functionality would be pretty much exactly the same as the purging system.

Version 0.21 released!
Download here: http://goo.gl/PsBCbK

Changelog:

• AI controlled ships can now move around, and warships will actively hunt down your submarine if you are detected. Sonar is now simulated for all warships which were historically equipped with it. Anti submarine weapons are also simulated: many warships are equipped with depth charges, ASROC missiles or mortar systems like the RBU-6000. Evading destroyers is now a real challenge! If detected it's best to stay submerged, move slowly (less than 5 knots is best) and try to either escape or reach a position where you can launch a torpedo at the attacker.
• Passive sonar is now simulated for your submarine. Note that the sonar display is clearest while moving slowly and completely submerged - moving quickly, especially while surfaced, will add a lot of noise to the display and make identifying contacts difficult. Your sonar has a 'blind spot' directly behind your submarine due to interference from the submarine itself. No active sonar, narrowband info or towed arrays yet but they're planned for future updates.
• Related environmental effects are also simulated, like the thermal layer in water which can distort sonar signals. The depth of the thermal layer varies with ambient temperature, currents etc but it is generally shallow (or non-existent) near the poles and deep near the equator. It is marked in blue on your depth gauge.
• Bilge pumps have been added. Select them like a control panel and press + or - to turn the pump up or down, or Z to toggle the pump fully on/fully off. Pumps are more effective at shallow depths.
• The submarine layout has been changed slightly.
• It is now possible to replace lost coolant fluid in the nuclear reactors. The coolant reservoir is simulated (part of the primary coolant pump) and will take damage over time as coolant leaks out. Stopping the leak then repairing the reservoir will replace the coolant. It's important to identify the source of the leak and fix it BEFORE you repair the reservoir, otherwise the coolant may leak out faster than you can refill it.
• Added a couple more ship classes and weapon types.
• Made explosions slightly less common and slightly more damaging.
• Several other bugfixes, including tweaking the rates for oxygen use in the diesel engines and the rate crewmen breathe.

Enjoy! As a special request, could you please let me know how difficult (or how easy) you find fighting destroyers, frigates etc?
(A good way to get some quick action is to play as West Germany and immediately sail east to Rostock, where you will almost always find some East German ships)