“Ripley steps out, WEARING TWO TONS OF HARDENED STEEL. THE POWER LOADER. Like medieval armour with the power of a bulldozer.

~ Aliens script, by James Cameron, September 1985.

In James Cameron’s Xenogenesis the two protagonists, a man and a woman, are hounded by a gigantic robot. The woman manages to flee, but the other is forced over a precipice and hangs perilously over a chasm. The robot leans in to finish him, but a far-off wall panel is forced open, revealing the woman – now encased in a robotic vehicle and ready to do battle for her partner’s life.

The scene was transplanted directly into the climax of Aliens, with the two nameless protagonists replaced by Ripley and Newt. There is no chasm; instead Newt cowers under the Sulaco’s flooring. The Alien Queen takes the place of the robot, the design of which Cameron would recycle for the Hunter-Killer Tank in Terminator. And the woman’s robotic vehicle is replaced by one of the film’s most iconic inventions: a mechanised exo-suit called the ‘powerloader’.

“When I was young,” Cameron told astralgia.com when discussing Xenogenesis’ mechanical ‘outfit’, “my friends and I did this little film with $20,000 from the rich, Mormon dentists out in Orange County … The story we wanted took place on a colony starship bound for another planet with the last remnants of humanity on board frozen. I came up with a device I called ‘the Spider’ that was used to crawl around the outside of the ship to make repairs. It was a four-legged walking machine that used a tele-presence-type amplification: you put your feet in things, you grabbed onto these controls, and however you moved and walked, it duplicated your actions.”

When Cameron wrote Aliens he retooled it from one of his unmade scripts, Mother, and also brought over Xenogenesis’ mechanised vehicle, changing it from a four-legged contraption to a two-legged exo-suit: “A year and a half [after Xenogenesis], The Empire Strikes Back came out with these big walking machines in it. I felt vaguely ripped off, or scooped would be more accurate. So I changed ‘the Spider’ to more of an upright, forklift exoskeleton concept.”

“I don’t remember exactly the origin of the idea. It’s based on a design that I created a few years ago for another story that never got made [Xenogenesis]. That predated the ‘Transformer’ robots, at least as a fad in this country. I think that the exo-skeleton concept has been used in a lot of literary SF.”

~ James Cameron, Lofficier interview, 1986.

Funnily enough, the AT-AT design from Empire was inspired by Syd Mead, who Cameron would later briefly task to design the powerloader. Former ILM employee Joe Johnson told btlnews.com in 2010 that “The snow walkers were from a brochure by Syd Mead for US Steel of these walking trucks going through the snow – we turned them into walking tanks.”

“I started designing it when they went to Pinewood. They constructed the test model with 2x2s and trash bags stuffed with newspapers to get the articulation down. The finished prop was so cumbersome, they had to have guys in black skin suits running it. It was not power operated, it was operated by manipulators out of shot.”

~ Syd Mead, Vulture.com. 2013.

Cameron decided to use the powerloader because he did not want Ripley to have the safe distance that a gun could give her when fighting the Queen. Instead she would have to physically tangle with her enemy in an atavistic display of motherly instinct. “I wanted to have the final confrontation with the Alien be a hand-to-hand fight,” Cameron said about the origin of the scene. “To be a very intense, personal thing, not done with guns, which are a remote way of killing. Also, guns carry a lot of other connotations as well. But to really go one on one with the creature was my goal. It made sense that Ripley could win if she could equalise the odds. So there had to be some way of amplifying her strength, in a way that was not a comic-bookish sort of concept, like taking a pill.”

“At a certain point, I was toying with the idea of having the Marines have battle suits,” he said, taking a page or two out of Heinlein’s Starship Troopers. “But then I thought, ‘oh, no, you’re going to see that coming a mile away’. Anyway, how would Ripley know how to operate a battle suit? They wouldn’t be teaching her. It was really critical to the story that she emerge under pressure as the person who really takes control. They discredit her at the beginning; the last thing they’d do is hand her a gun and teach her how to use a battle suit.”

Cameron discarded the idea of using a battlesuit (a weapon) and stuck with the concept of a mechanoid forklift (a tool). But he still wanted to assure the audience that Ripley could operate it. Depicting the powerloader as a rather rudimentary device (at least in the world of Alien) enabled Ripley to use it with relative ease.

“She had had to support herself as a dockworker at Gateway Station [so] it was logical to assume that she might know how to handle a basic piece of cargo handling equipment,” said Cameron. “You had to set it up. You had to see her volunteer to help unload the ship and impress them all that she could do it. Otherwise you’d never believe that she could duke it out with the Alien Queen.”

In Cameron’s original treatment the powerloader is revealed during the climax before it walks into the hanger to fight the Queen. The treatment describes a sequence of shots showing Ripley strap herself into the suit. We are then given a full shot of Ripley in the powerloader. Cameron omitted this in later scripts (but kept the cuts of her strapping in to something) to get the money shot we know from the film. The shots of her strapping in were kept in all of the subsequent drafts, but none of it was ever shot (though many fans believed that the footage had in fact been filmed – it’s usually recounted in those ‘I saw a different version on TV as a kid’ stories).

“I was particularly proud of being involved in the sequence involving the Alien Queen and the powerloader,” said Special Effects technician Joss Williams, “because right from the start of my involvement on the movie, we had pictures drawn by Jim -of which today you’d get computer generated images, but this was hand drawn by Jim- of the powerloader fighting the Alien Queen.” Turning Cameron’s painting into a reality would require not only full-scale models but miniatures as well.

Building the large powerloader was left to Special Effects Supervisor John Richardson. Richardson’s tenure on the film see-sawed from having near total control of his workshop, to suddenly working under Cameron’s peregrine-eyed supervision. The director would often check in and make amendments to the design, offering sketches to a bemused Richardson. “A lot of directors would have said, ‘I want it to look like a walking forklift,’ and let it go at that,” Richardson told Cinefex in 1986. “Jim would say, ‘I want it to look like a walking forklift and those little bolts up there have to be this shape.'”

“Jim is a very hands-on director,” Richardson explained further. “We were trying to cut just as many corners as we could just to get it ready in time, but Jim would suddenly get locked in on the shape of the screw head in the back corner of the heel of the boot. And we were just screaming to get the thing ready.”

The two would quarrel over the details, but they unanimously agreed that the outcome was the better for it. Richardson recalled that “I seem to remember once or twice on a Friday night, a bottle of champagne would turn up in the workshop with a little note from Jim saying, ‘Building powerloaders is thirsty work. Have one on me.’ And it sort of smoothed everything out until the Monday … They were good times.”

The delays with the large powerloader meant that delays with the miniature were inevitable, since the miniature was based directly on the larger model. “They were working on the full size one right up until the time they started shooting it,” said miniature designer Phil Notaro, who helped build the Queen and powerloader miniatures with Doug Beswick, “so I actually couldn’t finish the puppet until I got over there [to Pinewood studios] and saw it. ‘Aha! That’s what it looks like!’ … It was pretty tense for a while there, though, because we were halfway into our schedule and we hadn’t even started the powerloader yet.”

The final battle between Ripley and the Alien Queen was among the last scenes to be shot for the film. The full scale powerloader, weighing around 600lbs and fabricated out of aluminium, fibreglass and PVC plastic, was controlled from within by a stuntman (John Lees) who was obscured inside the machine – just like the Alien Queen puppet, which contained two stuntmen. “I remember the English visual effects guys thinking we were crazy,” said Cameron, “the way we wanted to do it. And I said, ‘No, it’s the gag where the dad lets the daughter walk on his feet.’”

The back of the prop was given hidden counterweights disguised as machine components. The mechanics inside the hands were crafted to be light enough so the whole thing wouldn’t fall face first into the ground (Weaver related that this happened many times in rehearsal). The wrists were radio controlled. The ‘pincers’ were operated by cables. Also like the Queen puppet, the powerloader was held up by a rig (expertly hidden by Cameron’s framing) for its entrance into the hanger bay. For other scenes it was supported by a pole up the spine or by a counterweighted crane.

Sigourney Weaver, by all accounts, was very professional when it came to being strapped inside the contraption or placed on the sidelines all day. Cameron had predicted that the effects-heavy scenes would require many takes, re-calibration, and luck to get right. Weaver, he reckoned, would be naturally bored and tired during such a complex process, but the opposite was true. “She was just wonderful about the whole thing,” Cameron said. “She was a complete pro and very tolerant when it came to standing around the set for hours doing the predicted take after take.” Weaver herself felt that the sequence was worth it. “I loved that,” she said. “That’s, I think, one of the favourite moments that people have: that battle, ‘get away from her, you bitch!'”

But Weaver did have to contend with one uncomfortable element during the shooting: the effects team’s sense of humour – a balloon was inserted into the powerloader, just behind Weaver’s buttocks. Whenever the camera rolled, the crew would pump air into the balloon through a pipe. Weaver ran through several explanations for the bulge at her backside, with some involving the stuntman, John Lees, concealed behind her. “She thought he was getting a boner all the time,” laughed Richardson. “She was going, ‘John, John? What are you doing, John?’ She couldn’t move because she was strapped in, and (John) didn’t know because he was nowhere to be seen [inside the loader].”

“It was very funny,” said Weaver, “because it lasted quite a long time, a couple of hours. I was thinking, ‘Well, this is interesting.'”

The scenes featuring the miniature loader and Queen were filmed after principal photography had ended. The powerloader miniature was moved around a small scale set by rods placed through the floor and the model’s feet. The arms were cable operated. The model was fitted with a small doll in the form of Ripley. For the scene earlier in the film where Ripley demonstrates her prowess with the loader for Hicks and Apone, we can see another powerloader being operated in the background – this was a miniature plate filmed much later; the pilot is in fact the Ripley doll redressed as a Marine.

The miniature powerloader’s final scene, tumbling out of the airlock, was literally its final scene: the model allegedly plummeted through the star field backdrop and smashed to pieces on the concrete. “We did about eight takes on it,” said Notaro, “and each time it crashed into pieces. We’d then have to superglue it back together and do it again.” On the ninth shot the miniature broke beyond repair. “It exploded,” recalled miniatures technical supervisor Pat McClung.

Cameron had worried that the scene with the powerloader would not be taken seriously by the audience if it was anything short of stellar – if the images in his head could be conjured and guided by an expert (and careful) hand, then he figured they would accept it. It would all hinge on the execution. “There are always certain things on every film that you’re nervous about,” he said. “You like the challenge. The challenge is, can I make the audience believe this? Then you’re nervous about it the whole time, which is good. The more nervous you are, the more you’re going to set it up and make it work.”

“It always stuck in my mind,” said Joss Williams, “and it still does today – the sequence when we actually shot it onstage at Pinewood of the powerloader that we built and seeing the Alien Queen that Stan Winston had built, fighting. And it was just what Jim had drawn some eighteen months, maybe two years, previously.”

“When the film opened,” explained Cameron, “I went to the Egyptian Theatre in Hollywood. When the spaceship door came up, and there was Sigourney in the powerloader, the audience went apeshit! That’s what it’s all about. It really taught me to not be afraid of the challenges, to find them, to seek them out because that’s where the magic is.”