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HOI4 Dev Diary - Railway guns never tire

Hello there, C0RAX again.

It’s time again to reveal some more secret information that was hinted at in the last dev diary. Specifically this week will be revolving around the final part of railways and trains. So without any more need for introduction here are our stars of the show today.

The railway guns.

So to start off I'll go through how you get a railway gun on the map because it’s a little different to normal land units. First of all you are going to want to research railway guns which comes after armoured trains.
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Then you can find it in your production tab just like building normal equipment. But unlike other equipment you build, these production lines are limited to 5 factories and the railway gun won't be added to your stockpile.
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Instead, once completed, your brand new railway gun will appear in your capital, in this way they are built similar to capital ships.
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Moving your railway gun is limited to provinces with railways, and so to get to the front you must have a rail connection. Taking into account the rail conversion time when capturing territory is important as you will have to wait for the big guns to be able to help you out.
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You can also attach railway guns to armies just like with planes and they will attempt to place themselves relative to the frontline. If you have several, they will be distributed where possible to support your army. There is also a quick select button on the army to select all railways guns attached to an army should you need to.
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Finally, the last bit of control understanding is range. Railway guns have a range in which they can support and so from any one point are limited in which provinces they can support. This range is shown by hovering over the unit icon.
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On to combat now, here we can see a combat with a supporting railway gun, we have added the useful icon on the combat progress indicator that there is a supporting bombardment. This new icon will also show if there is shore bombardment happening in the combat.
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The combat effects of railway gun bombardment work just like shore bombardment, causing negative combat stat modifiers to those on the receiving end of the big guns. These modifiers affect both soft and hard attack as well as defense values. Notably, these effects do not stack - it becomes more important to spread out your railway artillery than to concentrate it.
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Finally we need to talk about capture and damage, railway guns can be captured via encircling them and damaged by damaging the railway they are placed upon.

Now railway guns are the biggest guns by far used on land and so it's important that we have representations of those built by the major powers. So now we look at the unique guns for the major powers.

This is the German Schwerer Gustav model you will see when playing as the Germans. It's perhaps the most famous railway gun and definitely the biggest and so had to have a part in this feature.
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This is the BL 9.2inch railway gun, a relic of the first world war but these big guns were kept in service until 1945.
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Following that we have the French Canon de 305 another veteran of the first world war.
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Next up is the USA’s 8-inch Mk. VI which remarkably first entered service as late as 1941!
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Type 90 240 mm railway gun whose claim to fame is being destroyed by the retreating Japanese in the soviet invasion manchuria.
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And finally the TM-3-12, three of these were made in 1938 and were used in the winter war against finland, unbelievably these where in service until 1999 (a whopping 61 years of service)
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Finally here's a cool clip of the Schwerer Gustav firing in game.
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I would like to ask: Would be possible to add the bombardment feature (range and other related things) for modders? For example, modern mods (cold war era, modern era) could use it as long range missile launchers, or if it's possible, anti-ship weaponry. Also, for projects like the Ace Combat one, with superweapons, would be a nice feature to play with.
 
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I would like to ask: Would be possible to add the bombardment feature (range and other related things) for modders?
Or maybe even the bombardment feature for field artillery?
 
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Never actually understood the hype as railway guns have very limited uses IRL and were quickly made obsolete by the rapid military movement and aerial bombardment innovations. Even the Gustav fired only 47 rounds at Sevastopol, which damaged a negligible part of the city compared to regular artillery which has fired 13000 shells at it. They are slow to dismantle and even slower to assemble, had to only traverse railways, and actually ate unneeded resources as they consume a more different type of ammunition.

I think the only thing that I liked here is the added functionality for modders. It would now be possible to for example, experiment on only shipping troops and supplies to the Mojave by monorail from Shady Sands, or even have Topol-Ms in TNO and Millennium Dawn.
 
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Here's an idea if there's ever time: Split railway artillery into heavy artillery and siege artillery. The former is stuff like the K5, French 274mm guns, and other 9-12" guns, while the latter is insane enormous cannons like Schwerer Gustav, the BL 18-inch railway howitzer, and Obusier de 520 modèle 1916.

The former gives normal combat buffs and some bonuses against forts, the latter gives relatively little bonus in regular combat but absolutely wrecks heavy forts.
 
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The image with the Schwerer Gustav standing at a right angle to the tracks first made me laugh, but then ask myself, how did they aim those big guns? Did they have to put down new track in the right direction? I doubt the cannon could turn, lest it would flip the whole cart! o_O
From what I've read, part of the slow rate of fire and overall inefficiency of Schwerer Gustav was because the Germans had to lay two or three spur lines of track , measuring hundreds of meters, just to deploy and aim the silly thing without blocking the main rail line.
 
While I am glad to see railway artillery being added to the game, it seems to be as I feared, in that PDX mostly just went for representing the huge railway guns, rather than covering all the bases. The fact there's just one type of railway artillery, and it's hideously expensive, seems to back this up. Historically many small countries fielded railway artillery because it was worth doing. But why would in-game IC-starved minors ever bother with something that costs 800 production cost and a slew of resources they probably won't have? Seems like a fool's errand to me.

During WW2 for instance Finland used at least 11 railway guns: 4x152mm, 4x180mm and 3x350mm. 10 of those were put into service during WW2. I don't see fielding even one in the game being worth it for a minor like Finland, even if we assume one in-game railway artillery unit to be a full battery.

Just like not every plane was a B-29 and not every tank was a Maus, not every railway gun was a Schwerer Gustav.

I would also like to know, can I mod the feature to represent things like coastal batteries? I have a feeling the answer is no because it'll be hardcoded like fuel, but please say I'm wrong on this.
It's actually the other way around as the rules presented are for smaller tactical support artillery, even if they use images of larger guns. Considering the range so would it only require one to cover the Finnish defensive line and most likely be worth the cost.
 
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The image with the Schwerer Gustav standing at a right angle to the tracks first made me laugh, but then ask myself, how did they aim those big guns? Did they have to put down new track in the right direction? I doubt the cannon could turn, lest it would flip the whole cart! o_O
There were four main ways. For smaller railway guns, you had what were essentially turret mounts. For larger guns, there were two main systems - limited traverse carriages and turntables. Gustav used a different system where they laid a large curved section of track and the gun would roll forwards or backwards on this track to set its angle.
 
It's actually the other way around as the rules presented are for smaller tactical support artillery, even if they use images of larger guns. Considering the range so would it only require one to cover the Finnish defensive line and most likely be worth the cost.

For the price of one in-game railway gun/battery you can get almost 30 Heavy Tank IIs, which represent vehicles like Tiger Is and KVs. It's clear that the cost is based on the heavier railway guns. What they should've done was provide us with several types of railway artillery. The current approach is analogous to lumping a Spitfire together with a B-17 and calling the technology a plane.
 
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Isn't that overpowered then? 1 train that, historically shot 14 times a day, and had terrible accuracy, is going to give a -15% defensive debuff to all enemy units in range?
I understand you have to make it worth. But, shouldn't it maybe be repurposed for sieges?
I'm pretty sure they represent Batteries, not single guns (Gustav is just fluff text like all other names). Think the 28 cm Krupp K5(E) with a RoF of 15/hour not the 80cm Gustav with a RoF of 1 every 30-40 minutes (the 14/day wasn't its maximum.)
 
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They weren't. But if you ever wanted to park a fleet next to Switzerland to bust a fort, it's pretty alright.

I'm more curious why forts are purely defensive, and we can't put naval guns in them, instead of on rails.
I have always wanted something like a Wunderwaffen DLC. I even made a forum post a while ago asking for things like editing tanks like you can navy. But I really wanted stuff like being able to customize forts. Being able to install 460mm Naval Cannons made out of pure steel. It would cost an astronomical amount and repairing it wouldn't be easy also. But would be super effective. On the flip side, you could make a little dug-in wood/dirt hut with just an MG. I want to be able to make Fortress Albania!
 
For the price of one in-game railway gun/battery you can get almost 30 Heavy Tank IIs, which represent vehicles like Tiger Is and KVs. It's clear that the cost is based on the heavier railway guns. What they should've done was provide us with several types of railway artillery. The current approach is analogous to lumping a Spitfire together with a B-17 and calling the technology a plane.
The cost is because it's so strong that it provides more support then all the Finnish railway artillery combined did. To continue your annology, it costs like a B-17 because it acts like several wings of Spitfires. It still does the job of "Spitfires".
 
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The cost is because it's so strong that it provides more support then all the Finnish railway artillery combined did. To continue your annology, it costs like a B-17 because it acts like several wings of Spitfires. It still does the job of "Spitfires".

That's yet another issue. But instead of saying "well you know, it's fine because this other thing they've done is screwed up too", I say fix them both: cost and effectiveness. And give us a distinction between a 152mm gun and an 800mm gun to boot.
 
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As I mention elsewhere, despite being iconic, Gustav was an outlier. A more sensible (and far more common) railway gun like the French 194mm TAZ modèle 70/94 could do two rounds per minute. Even amongst larger bore railway guns like the French 274mm GI modèle 17 and German 28cm K5, you're looking at about 15 rounds per hour. All of these weapons were far more numerous than Gustav and should be taken as better examples of typical railway guns.
OK, but were they still accurate and flexible enough to hit specific tactical targets? If not a moving tank, than at least a specific enemy formation? I know nothing about them, so am genuinely interested. However, to me as a layman it seems like they should play a role similar to strategic bombing, not provide a combat bonus.
 
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OK, but were they still accurate and flexible enough to hit specific tactical targets? If not a moving tank, than at least a specific enemy formation? I know nothing about them, so am genuinely interested. However, to me as a layman it seems like they should play a role similar to strategic bombing, not provide a combat bonus.

To give an example, in January 1940 Finnish railway artillery probably* destroyed a Russian divisional HQ, killing the divisional commander. The artillery in question was a single 152/45 CRaut, which is the Finnish designation for the railway artillery version of the 152mm 45 calibre Pattern 1892 Canet naval gun.

*Source is wartime Finnish radio intelligence and I haven't cross-referenced Russian sources to verify it (not such a simple matter to do so on such a topic).
 
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Remember the Siege Artillery Command Ability exists and that is what represents fort specific artillery and smaller RW Guns used for this purpose, having the larger RW Guns only damage forts might be more accurate but would also be an incredibly niche unit not worthy of the significant art investment of the 3D models, animations and so on.
 
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Loving this development, however I wish there were two types, a superheavy bunker buster with an AoE anti-fort and anti-city effect, along with a more lightweight railway gun that gives the RG effect already implemented here. Maybe in the future?
Totally agree, maybe be able to specify target locations for the heavy ones as well, so you can use them on the actually important things.
 
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There should be a slightly more expensive super-heavy variant that would have options for a strategic outpost on cities, fortified posts or coastal defense, as historically the Gustav and the Dora were.
 
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