|This is a chapter article.|
This page covers a single section of the game. For the full plot overview, see the game's associated storyline page.
Blast Pit is the sixth chapter of Half-Life. The main goal is to kill the Tentacles by activating a rocket engine. It takes place in Silo D, a large abandoned Cold War era missile silo that was used as rocket test labs.
- For the story information, see the Half-Life storyline article.
In the previous chapter, a scientist tells Gordon that the science team at the Lambda Complex might be able to end the catastrophe. He can reach there by going through the decommissioned rail system beyond the silo complex. According to the strategy guide, the Marines haven't located this area yet, which explains the lack of human enemies in the chapter.
The chapter starts in an abandoned rail tunnel that leads to the silo. Inside the silo, there are huge Tentacle creatures, who act as boss characters. Here, there is a dying scientist tells Gordon to fire the rocket engine to kill the Tentacle creatures before they grow any larger. In order to fire the rocket engine, the player must restore the power, oxygen, and fuel; which requires the player to get into the inner chamber of the silo to reach other areas, while avoiding the Tentacles.
The Tentacles rely on sound to locate the player. The player can either crawl (to minimize their movement noise) to sneak past, or use the grenades to distract them. It is impossible to kill them using regular weapons. Restoring the resources, and activating the rocket engine kills the Tentacles, and reveals a set of tunnels, which leads to a hub used for Materials Transport in Sector E.
The silo is known as Silo D-002 in this version. It is located at the center of a large warehouse complex. The entrance to the silo is seen at the beginning of the chapter The Security Complex, but is inaccessible. The actual chapter is not included in the game. The silo itself is only seen in a technology demonstration (map silodemo) used for showcasing the Tentacles.
There appears to be a hidden room under the Tentacles, that can be only reached by using the noclip mode. The entire area is textured in a pure black color, making it impossible to see under normal circumstances. The player was most likely had to kill the Tentacles to access the room. Furthermore, the brush work in the room matches an area shown with a group of Houndeyes in one of the early screenshots.
The levels were slightly updated for the console ports. The area with the lift that takes the player up to the silo is much more detailed in the PlayStation 2 version. The storage room under the pipe that collapses (when the player walks through it) is flooded in the Dreamcast version. The level code for the chapter is "Safe And Sound" in the Dreamcast version. The security guard who yells and shoots at the Tentacles is not present in the console ports.
 Behind the scenes
- “There was a silo and there was a plan that there was going to be a monster, some form of a tentacle that was going to grab a security guard or scientist and kill them. And it was just a simple thing where you went in there and pushed these buttons on the console and fired the rocket launcher and part of the engine burned [it] to a crisp. This just seemed to simple. So when we started to take it apart on paper, we had all these extra paths. Let's basically put all these obstacles here; let's break these down into components. Let's create all these rooms you've got to go through and all these puzzles you have to solve. They all feed back to the main puzzle so that when you finally push those three buttons you've done so many other things leading up to that moment, it's going to be a lot more significant at that moment.”
- — Marc Laidlaw
The chapter went through many changes during its development. The early version of the silo was used as the abandoned flooded silo in the chapter Apprehension. The yellow train from the multiplayer map Subtransit was originally created for the abandoned rail system section of this chapter, but was replaced. The original chapter title was Screams and Whispers. Unused Black Mesa Announcement System lines for the chapter can be found in the sentences file used for the speech system. The name of the chapter is "Experimental Propulsion Labs, Silo D" in the document.
The player was to come across two security guards in the old decommissioned rail system. There is a screenshot showing a possible location for the scene. The first guard was to be in an observation tower, looking down at other guard who was on the tracks, inspecting something. When the first guard sees the player's out-of-control train, he was to warn his friend, and then the player by waving at him. The guard was to pull a lever (the purpose of this lever is unknown), but break it, and fall down on his back; while the other guard was to climb on the sidewalk, and escape from the train. The animations for this scene can be found in Day One.[i]
While the Cabal version (named Tentacle Silo) of the chapter is close to the final version, there were several differences. The chapter was to start in the control room of the silo. In order to get the rocket engine to test fire, the player had to turn on the safety hatch next to the engine. The only access to the silo was through an elevator, which was to take the player to the ground level. From here, the player could climb up, while avoiding falling platforms, to reach the oxygen and fuel tanks, and the power generator through tunnels used for pipes/cables on top.
In the vertical shaft (wind tunnel), the player was to push explosive canisters into the massive fan to make them fly up, and destroy the obstructions on the ceiling. The generator was located in a room populated with Stukabats, beyond Automatic Machine Shop, an area with mechanical robotic arms. Like in the final game, killing the Tentacles was to reveal a room (named Tentacle's Lair) with piles of collected junk, dead bodies, a coke machine, and a Colt Python. Nodes (used as landing spots) for Stukabats can be found in the maps c1a4b and c1a4f.
Background map in Half-Life: Source.
 Associated media
- Additional images related to Blast Pit