Source-checkedVehicles & ships

WH4-L3 Humpback Retrofitted

by Gregorius25 · for Barotrauma

The WH4-L3 model commonly known as the Humpback became a common sight in the treacherous oceans of Europa. Tough, reliable, and efficient. Those submarines have a service record exceeding any other…

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2 yr agoLast updated
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About WH4-L3 Humpback Retrofitted

From Steam Workshop

The WH4-L3 model commonly known as the Humpback became a common sight in the treacherous oceans of Europa. Tough, reliable, and efficient. Those submarines have a service record exceeding any other…

The WH4-L3 model commonly known as the Humpback became a common sight in the treacherous oceans of Europa. Tough, reliable, and efficient. Those submarines have a service record exceeding any other military vessel built on Europa and played a huge role in the early days of the Europa Coalition. However, times have changed and the good old Humpback has become somewhat… aged. Most of the Humpbacks built in the 21st century have already said their tears in the rain monologue about the “attack ships on fire” and “pulse lasers glittering in the dark near the Tannhauser Gate” and have been since scrapped or are still rotting somewhere at anchorage. Fortunately for this particular vessel, it wasn’t time to die. The coalition admiralty decided to retrofit some of the decommissioned Humpbacks in order to send them to action against the Separatists. Three prototypes were built and put to sea trial, however, despite excellent initial performance during, the project was canceled due to budget cuts, and the existing prototypes were sold to private owners.

This modification intends to improve on the beloved Humpback and make it more capable without making it too OP. My aim was to make it lore-friendly and to keep the improvements realistic - mainly with career mode in mind. However, I also created a multiplayer version of the sub with all guns already installed and with more provisions on board if you just want to screw around. In addition, I scattered 7 retrofit logs around the sub to add some lore to the project.

[h1]Features[/h1]

Energy Recovery System

This vessel is outfitted with an Energy Recovery System(ERS) that allows to minimize excessive overvoltage. When the load in the grid suddenly drops and the output significantly exceeds the load, the system will automatically change the recharge rate of the battery array to absorb the excessive power. "ERS Active" notification will appear on the battery status monitoring screen when this takes place. This system is designed to minimize damage taken by the junction boxes during overvoltage and provide auxiliary power when undervoltaged. When the load is greater than the output, the battery array will discharge to the grid until the reactor catches up. With this system, the batteries are NOT meant to be fully charged when sailing. Keep the battery charge level somewhere between 40 and 85%. The battery will be charged automatically at outposts. Use manual loading if you feel that the current charge level is too low.

"Okay, cool, but why not just add a reactor auto-controller?" For the same reason, the devs nerfed them in Hoist the Sails update. The output/load balancing is in the game for a reason and auto-controllers are just too OP. Granted that this system also doesn't require you to control the reactor manually but for me, this solution is more fun at least.

Center Console

The center console allows you to:

  • View remaining fuel and battery level
  • Monitor current power output and ship’s power consumption
  • Receive notification when overvoltage is detected and when the ERS system is active
  • Quickly disable all exterior lights and manually switch to emergency lighting
  • Enable or disable manual charging
  • Switch to “Rig For Red” mode to preserve night vision in the command room
  • Use the status monitor
  • Change the rate for the battery manual charging, supercapacitor recharge rate and read about sub’s systems in the terminal.

Emergency Power and Auto-Charging While Docked

When the sub is docked, the reactor shuts off, power is leeched from the station and batteries are charged automatically. When the reactor is offline, the Emergency Power System is activated automatically. When EPS is active, batteries provide backup power and the vessel's functions are altered in the following way: 1. Engine power reduced to 25% 2. All standard lights are switched off. Emergency lighting is enabled instead. 3. Fabricators, deconstructors, and research stations are disabled.

Normal lightning

Emergency lightning

Smart ballast hatches and auto doors

When it comes to water flow, hatches are far more effective than duck blocks. But exactly how much more effective? My simulations showed that fully draining the command room from 100% water level to 0% using a single duct block would take 51,01s. That’s almost a full minute of slowly wading in water during the most critical moments when you desperately need to man the guns or get to the navigation console. Using a hatch to drain the same amount of water takes only 13,33s. That’s almost a 74% increase. This is where the smart ballast hatches system comes in.

The ballast room hatches will open when sensors detect water in the room directly above them. The water from the command room and the engine room drains down to the ballast rooms where it can be pumped out from the sub using the powerful Vole C model ballast pumps. The hatches close if no more water is detected in the rooms above or if the water level in the ballast room is already above 90%, preventing any water from coming in from the ballast room to the command room/engine room. This solution greatly improves the water flow and helps to deflood the command room and the engine room much faster compared to just waiting for water to drain to the bilge through duct blocks. It also greatly reduces the time during which your electronic devices take water damage.

Read the full description on Steam Workshop →

Highlights

From source data

Footprint

Rated a light load on a server.

Last update

Its author last shipped an update 2 yr ago.

WH4-L3 Humpback Retrofitted on Nxeon

From our catalogue
One-click install
Not available. One-click install isn't available for this game's mods yet. Download it and upload it to your server in Files.
Server load
light
Smallest plan we suggest
Barotrauma — 2 GB (2 GB RAM). This follows our own load rating above, not a benchmark.
Latest build
2024-07-21, released 2024-07-21

Game versions by loader

LoaderGame versionsNewest
Workshop

From 1 recorded build of WH4-L3 Humpback Retrofitted.

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What kind of mod it is

From the catalog
Listed on Steam Workshop as “Workshop”

Vehicles & ships

Cars, boats, aircraft, ships and other things to drive or fly.

Compatibility

Game
Barotrauma

Verified at the source

  • ✓Steam WorkshopOfficial listing, checked 2026-10-10Open ↗
  • ✓AuthorGregorius25, as published on Steam Workshop
  • ✓LicenseNot published by the sourceFree

WH4-L3 Humpback Retrofitted, answered

Generated from the mod’s own source data.

Is it free?

Yes. WH4-L3 Humpback Retrofitted is free to download from Steam Workshop.

How do I add it to my Nxeon server?

One-click install isn't available for this game's mods yet. Download WH4-L3 Humpback Retrofitted from Steam Workshop and upload it to your Nxeon Barotrauma server in Files.

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