The fourth Era has 3 passenger engines named ancient gods and heroes, with one being a bonus engine.
You can open new engines by using research points generated by the Laboratory building within your Train Station. Only when you've researched the required pre-requisites, can you begin to develop the next engine. At the end of each era, a coupling system is available, allowing engines to transport goods from the next era.
You dont need to research anything from previeous eras to start using your research points on Era 4 engines. So if you start late into the game, you can ignore earlier Eras, if you wish.
If you want to compare all the engines, have a look at our Passenger Engine Comparison article.
Requirements:
• Research the Apollo cargo engine
• Research Tractive force I+II & Reliability upgrades
Research Cost: 50 Research Points
Starting Stats:
• Cost: $600,000 • Passengers: 45 • Reliability: 60%
• Acceleration: 10 /20 • Max. Speed: 240 km/h
You can research & buy these upgrades:
| Upgrade | Research Points | Upgrade Cost |
| +10% Reliability I | 8 | $50,000 |
| +10% Reliability II | 8 | $50,000 |
| +10 Passengers I | 14 | $100,000 |
| +10 Passengers II | 13 | $100,000 |
| + 6 Acceleration | 6 | $40,000 |
| + 20 km/h Max. speed I | 10 | $75,000 |
| + 20 km/h Max. speed II | 8 | $60,000 |
• The Acceleration, Reliability and the Max. speed Upgrades lead to next Cargo Train: The Thor
Requirements:
• Research the Horus or the Neptune & the required upgrades
Research Cost: 60 Research Points
Starting Stats:
• Cost: $1,500,000 • Passengers: 300 • Reliability: 20%
• Acceleration: 01 /20 • Max. Speed: 70 km/h
The Hypnos is a multi slot engine and takes 3 slots instead of only one.
You can research & buy these upgrades:
| Upgrade | Research Points | Upgrade Cost |
| +15% Reliability I | 11 | $200,000 |
| +15% Reliability II | 10 | $200,000 |
| + 50 Passengers I | 17 | $250,000 |
| + 40 Passengers II | 23 | $150,000 |
| + 1 Acceleration I | 15 | $400,000 |
| + 10 km/h Max. speed I | 10 | $300,000 |
| + 10 km/h Max. speed II | 14 | $250,000 |
• All the upgrades except Passengers II are needed for the next cargo Engine: The Poseidon
The Hades is the Passenger Bonus Engine of Era 4. It can be bought in
the Rail Nation Shop and can be won through the Lottery or by
entering competitions in Era 5
Starting Stats:
• Cost: 2,500 Gold • Passengers: 90 • Reliability: 80%
• Acceleration: 06 /20 • Max. Speed: 200 km/h
Note: The cost of the bonus train reduces if purchased in a later era.
The Passenger and Cargo engines for an era can also be purchased as a bundle from the Rail Nation Shop.
You can research & buy these upgrades:
| Upgrade | Upgrade Cost |
| + 10% Reliability | 100 Gold |
| +20 Passengers | 100 Gold |
| + 4 Acceleration | 100 Gold |
| +30 km/h Max. Speed | 100 Gold |