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Captain’s diary #44: Jump on the hype train for Update 3!

Ahoy everyone, Captain Marek here! Since the release of Update 2 in April, we've been busy stabilizing the game, fixing bugs, and planning our next steps. In today's diary post, I'd like to wrap up the Update 2 chapter and give you a sneak peek at what's coming in Update 3. So, let's dive in!

Update 2

Update 2 was a great success! Since its release, we've reached nearly 6,000 concurrent players, surpassing the numbers from Update 1. Our new COI Hub website is thriving with hundreds of maps created using the brand new map editor, and nearly a thousand blueprints have been uploaded so far. We greatly appreciate all the support and feedback from the community!

We’ve also seen some fantastic builds that you all share with us. Here is an awesome screenshot from a save shared by Reddit user PontusOverlord. He made this lovely organic build on the Armageddon map.

A save from PontusOverlord titled: “After 80 hours, my Spaghetti Island has finally reached space!” (Notice the rocket launching in the distance!)

Finally, I have an interesting statistic to share with you. Below is a pie chart showing map popularity based on games played in May 2024. The most popular map is Armageddon, accounting for 34% of all games played, followed closely by New Haven with 30%. Interestingly, over 15% of games are played on community-created maps. The standout among these is “All-in-One” by Undying29, which creatively combines all built-in maps into one large island and is played by 3% of all players. Around 5% of players are still playing on legacy pre-Update 2 maps.

Relative map popularity in May 2024.

What is your favorite map? Would you like to have any of the less popular maps changed or improved? What kind of map do you wish to have to play on? Let us know!

Update 3 hype train

Enough of Update 2. Now let’s switch tracks to the Update 3 and see what’s coming! In Captain’s diary #40 we already teased a prototype of roads – the #1 requested feature for Captain of Industry. Since then, we have developed this prototype a little further but had to drop it from Update 2 due to time constraints.

By doing this prototype, we’ve learned that implementing roads is a very complex task as they need to interact with all the other game mechanics such as dynamic terrain, blueprints, copy/paste, path-finding, etc, which makes their implementation labor intensive.

Another challenge comes from the grid. Captain of industry is a grid-based game and all entities need to conform to the grid in some way. For example, we can define all road pieces to start and end on the grid, so that they can be easily connected together. However, with this system, making a two-lane road that has end-points aligned to the grid while keeping a smooth turning radius is complex, especially for roads at 45 degrees. The picture below demonstrates this issue.

Left: 45-degree double-lane road, where the outer lane does not end on the grid (see the red dot). Right: Both lanes end on the grid, but the resulting road piece has a jagged edge, causing many issues down the line, especially in 3D rendering.

This is actually a more significant issue than it might sound from this one example, but it adds to the list of issues we must solve to make roads a reality.

With all of this in mind, we decided not to invest further work in roads for now because there are more exciting game features that we could be working on instead. Choo-Choo! Hop on the hype train! 🚂


That’s right! After long deliberations, we’ve concluded that trains are more exciting than roads for several reasons.

First, while roads are great for organizing truck traffic, they don’t introduce fundamentally new mechanics to the game. However, trains bring a new mechanic: long-range high-throughput transportation. As maps are getting larger and larger, the need for long-range transportation is growing, and we’ve seen so many playthroughs on the Armaggeddon map that were just begging for this type of transportation.

Second, train networks can be made extensible, unlike conveyor belts or pipes. Connecting a new location to a train network can provide access to all destinations within the network, making trains more versatile and easier to build than, say, tier 4 conveyors.

Third, trains will help alleviate pressure on truck logistics, freeing trucks for mining or local logistics. Roads wouldn’t solve this issue; in fact, they might make it worse by encouraging players to build highways for long-range truck deliveries, requiring even more vehicles.

And let’s be honest, trains are awesome! Who doesn’t love trains? They are the lifeblood of any industrial empire, offering unmatched efficiency and capacity. Picture a powerful locomotive chugging through scenic landscapes, connecting factories with mines and ports. It’s a sight to behold!

Rest assured, our work on trains doesn’t mean roads are off the table; it just means trains will arrive sooner.

Marek and trains

Before I tell you how trains will be implemented in Captain of Industry, let me preface this with a short personal story (feel free to skip for the train features below).

When I was a kid, my parents let me occasionally play games on their computer. The computer was running DOS, and I had no idea what was going on (I was 8 years old). An older friend helped me install two games on it: SimCity 2000 and Transport Tycoon Deluxe, and gave me the exact characters to type into the console to launch them. These games were my very first exposure to gaming and I was hooked!

To this day, I remember that my favorite TTD scenario to play was the “Mega Rail 1960”, a custom map where you start as an already developed company along 7 AI competitors. There was this aggressive pink AI that was always messing with me. The screenshot above is from OpenTTD which can still load the original TTD scenario files!

Since then, I’ve enjoyed many games with trains. I've played games such as OpenTTD, Railroad Tycoon, Chris Sawyer's Locomotion, Cities in Motion, and even more recent ones like Mashinky, Factorio, or Sweet Transit. Yet, OpenTTD is still the most enjoyable train sim in my eyes. I just love that you can create the most efficient train network with things like priority merges or pre-accelerated trains joining a main line. 

The point I am trying to make here is that I love games with trains and I care deeply about making things right. There are some games out there that implement “trains” just for the hype, but they are so heavily restricted that it’s sometimes just a point-to-point delivery with very little depth to it.

Since I played so many train games, I also have quite strong opinions about certain mechanics and features regarding trains and how they should work. We are even attempting to innovate here, but I am getting ahead of myself. Let’s talk about the features.

Train features

We are passionate about trains and have dedicated considerable time to designing them to be both easy and intuitive to use while maintaining our high standards for realism. In the following sections, I'll explain how we decided on various features.

Please note that any presented information is subject to change.

Trains availability

The very first decision was that trains should not be too far in the research tree. The earliest logical spot for trains is actually right after the steel research since train tracks, locomotives, and wagons all need steel – and a lot of it! Fortunately, steel comes right after Research 2 so getting to trains should be relatively quick. We are still thinking whether train buildings such as depot or stations should require Construction parts 3 (probably yes) and whether locomotives should require glass similar to T2 vehicles (probably yes) so feel free to let us know what you think.

The proposed position of train related unlocks in the research tree.

Train car types

The second decision was about the types of wagons. Captain of industry has three major groups of products: unit, loose, and fluids (liquids and gasses). We already have three types of transport, three types of storage, three types of cargo ship modules, so it should be no surprise that we considered having three types of wagons.

On the other hand, we have just one type of truck that automatically adjusts to the cargo, so the decision is not as clear cut as it might seem.

We feel that trains are usually made for specific purposes, and three types of wagons make sense in this case. Having more wagon types also makes the trains more visually interesting and recognizable.

It needs to be said that we are still considering making a special universal wagon type available as a toggleable difficulty setting for players who don’t want to be bothered by matching wagon types. Which camp are you on? Universal or specific wagons?

Prototypes of three types of wagons.

Our 3D artist has shown enthusiasm for creating more types of wagons to enhance the visual appeal of our trains. While he might be joking about wanting job security by working on wagons all year, the idea of specialized wagons for items like logs or steel is worth considering for the future. We’d love to hear your thoughts on this! Would you be interested in using highly specialized wagons?

Train stations

We plan to have a modularized approach where each station block will be the same size as a wagon, allowing players to build any station size they want. Each wagon type will have a matching station module. This is a similar approach to cargo ships. Train stations will have ports for conveyor belts and pipes, and each station can load or unload.

Train car lengths

The third decision we faced was about the lengths of locomotives and wagons (train cars in general). We had two options: either make all train cars a fixed size, ensuring each one has the same length, or allow variable lengths, where each train car can have an arbitrary length.

While variable lengths are more realistic and offer more freedom in 3D modeling, we ultimately decided against this option. We chose fixed train car lengths to ensure that loading and unloading stations align perfectly with the train cars, avoiding any alignment issues and simplifying the overall gameplay experience.

Initially, the train car length of 7 tiles (14 meters) was chosen. It’s quite realistic, even though it’s on the lower-end of real train sizes, but any longer wagons were taking too much space in the early game. Our artist has made some mocks of this size, and we’ve been experimenting with them for some time.

Initial prototype with 7-tile train cars. Trucks for scale.

Many things in Captain of Industry scale over time, and we felt trains should scale as well. Having the same 7-tile locomotives and wagons for the entire game felt a little underwhelming during testing.

Thus, we decided to revisit the 7-tile long train length decision and made new prototypes with the size of 5 tiles (tier 1) and the size of 10 tiles (tier 2). Since T2 is twice the length of T1, the station alignment is preserved, but locomotives and wagons can undergo substantial upgrades. These sizes are also quite realistic. It felt awesome to see large locomotives pulling long trains as an upgrade, so we kept this and tossed the 7-tile trains. We also considered length pairs of 6/12 and 4/8, but these were too big or too small, respectively.

Prototypes of tier 1 and 2 wagons. The idea is that T2 will have ~3x more capacity.

Turning radius

Next, let’s briefly discuss the turning radius. Typical freight trains have a minimum turning radius of around 100 meters (300 feet), equating to 50 tiles in-game. While we strive for realism, such a large turning radius would make trains very difficult to use, which is not our intention.

On the other end of the spectrum, some grid-based games feature trains that can turn very tightly, with radii as small as 2-10 tiles. For example, in OpenTTD, trains can make a 45-degree turn on a single tile. While convenient, this would not work in Captain of Industry.

After extensive testing with our 5 and 10 tile wagons, we found that the smallest usable turning radius is 14 tiles (24 meters). Though still quite tight, this radius prevents train cars from clipping into each other during turns. Therefore, we've chosen this as our tightest option for now.

Additionally, we wanted to offer more turning radius options for situations where space is less of a concern. We decided on radii of 14, 22, and 30 tiles. The plan includes implementing maximum speed restrictions on tighter turns to enhance realism and encourage players to build smoother turns. The relatively large gaps between the available radii make them easier to distinguish, and we can maintain a smaller number of unique rail pieces.

An early mock of various train car lengths on various turn radii. The radius of 16 tiles was not chosen because it does not form a good circle when composed of 45-degree segments.

Maximum slope of train tracks

The final feature I wanted to cover today is the slope (grade). Take a look at the picture below, what slope would you choose with regard to realism and gameplay convenience?

These are four different slope options from least steep to steepest. Which one would you choose?

Now that you've chosen your favorite slope, let's dive into the details. Slope #4 is a 1:4 ratio (1 unit up for every 4 units horizontally), which matches the terrain designations. Vehicles can also drive up this slope. Slope #3 has a 1:6 ratio, making it slightly less steep. Slope #2 is a 1:8 ratio, half as steep as #4. Finally, slope #1 is the least steep with a 1:16 ratio.

The slope of train tracks is typically measured in grade percentages, calculated as the quotient of the slope ratio. Our gentlest slope, 1:16, translates to a grade of 1/16 = 0.0625, or 6.25%. In real life, freight trains rarely traverse grades steeper than 3%. Interestingly, the limiting factor is not the locomotive's raw power but the insufficient friction of the locomotive’s wheels, which can cause them to slip. It's not uncommon for freight trains to stall on steep slopes, especially under adverse conditions like rain.

In the game, the 1:4 slope is the most convenient since it matches vehicles and terrain designations. However, it appears too steep visually, to the point it breaks the immersion. We decided on a 1:8 slope (12.5% grade, #2 in the picture) which, while still steep, allows trains to change elevation levels within a reasonable distance. To support this new slope, we are considering adding 1:8 terrain designations. Additionally, we’re exploring less steep slopes for players who prefer a more realistic experience, specifically 1:16 (6%) and 1:24 (4%), which is really close to the real grades for freight trains. Our new configurable game difficulty, introduced in Update 2, could include options to enhance train realism.

There were other constraints to the slope related to track piece lengths in turns, but more about that some other time. 


  • Trains will be available near steel in the research tree.

  • There will be three train car types for three major product categories: unit, loose, and fluid.

  • Train stations will be modular, with one module for one wagon.

  • Trains and wagons will have two major tiers. T1 will have 5-tile train cars, while T2 will be twice as long.

  • Train tracks will have a minimum turning radius of 14 tiles and larger radii will also be available.

  • Maximum grade (slope) of train tracks will be 12.5% (1:8), half as steep as what vehicles can drive on now.

There’s still much more to discuss regarding trains, including train track mechanics, train stations, train physics, and traffic control with semaphores, but I'll save those topics for next time.

I hope you enjoyed this in-depth look into our train design process. We’d love to hear your thoughts on Discord and Reddit. I will also be live-streaming this weekend on YouTube and Twitch so feel free to bring some questions there (subscribe to get notified). And that’s all for today, Captain Marek out.


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