The BridgeSpider Bot is another of R&D's single-function bots that can be sent along with troubleshooters to perform required tasks on command. The BridgeSpider's only function is to build wire bridges to allow troubleshooters into areas where chasms, holes, or similar terrain prevents access. This can be due to natural formations underground or Outside, or due to combat or sabotage by CMTs. The spider can build bridges of any length, depending on ceiling and wall foundation options. These bridges are, for simplicity, designed only for foot traffic, although larger versions of the bot exist to create vehicle bridges and the like. The bridge system is a cable suspension bridge, with 4 foundations on either side and ceiling foundations for middle spans.

Part 1: Creepy Crawly
The spider sits atop a wheeled chasis that it can disconnect from when building bridges. The wheels lock onto the spiderbot on either side. Note that the bot will not build a bridge if it cannot disconnect from the chasis, as the extra weight could prevent stability during construction. The spider chasis consists of (front to back) a robot head with scanners, a spike cannon that will fire lead wires for construction and support, a double trolley system that allows the bot to travel up and across wires or to switch between wires, a pair of arms, one for building couplings and foundations (far side) and one for measuring, cutting and setting wires (near side) and finally the drum of cable that the bot carries with it.

Part 2: Construction
The bot will respond to a laser-sighting device and will build a bridge as follows:

1. Once the laser sighting has been triggered, the bot will measure the distance from it's location to the laser point. It will then calculate how many spans will be required to reach the point. The bot can only build 2 types of spans:
• 
  End Span: are 50 meters across, and can support only themselves and the weight of half of another span, meaning that a bridge with no mid spans (ceiling mounted) can only cross a 100 meter gap.
• 
  Mid Spans: are 100 meters across, and can support themselves and half a span on each side, meaning that a middle span can extend two end spans by 100 meters at a time with 2 ceiling mounts each.
2. The bot will create a series of line drops between end and ceiling anchors, and will then proceed to lay the support lines for the last set of lines, which the troubleshooters can walk on. R&D may also give the troubleshooters a collection of plastic plates to put down as a footpath, but this is optional.
3. Once the bot is finished, it will return for the wheel-chasis and cross the bridge as a test (it will hang under the bridge) and wait for the troubleshooter holding the marker at the other end of the bridge. If that troubleshooter doesn't cross within an hour, it will travel back across the bridge and eventually return to R&D. The laser sight also has a "fault" button that signals the spider that something is wrong with the bridge, in which case the spider will trace back over the lines looking for failures.

Part 3: Bridge Physiccs
In theory, if there is enough ceiling to support it, the bridge can be any length. In practice, the maximum length is 500 meters (4 spans and the ends). This is partly due to the engineering problems of hanging bridges and the inherent lack of swing control. While the bridge will be structurally capable of supporting it's own weight and that of the troubleshooter team, the spider is not designed to build sway wires to prevent the center section from swinging. The process involved would require side or floor anchors, which the spider simply isn't programmed to look for or build. The net effect is that of a circular swing, like having a fishing weight on a line dangled from above. The end spans simply cannot compensate for the natural swinging motion prompted by the team moving on the wires. This will be a minor issue up to about 500 meters, and beyond that it will go from nauseating to deadly.

Part 4: Problems and Faults
The spider is not especially smart, most of it's processing lies in calculating weights and distances, not figuring out what's going on. If the troubleshooter tells it to build a span from the top of one table to the top of another, it won't bother figuring out that the bridge will be half a meter off of the floor, it will simply build the bridge. It will not, under any circumstances, build a bridge that is unstable or unsafe... except if the bridge is unsafe due to outside forces or as mentioned above. Outside forces include:

• WIND: Outside or in particularly large areas, air currents can cause stress on the bridge that the spider will not compensate for. Any high winds could unbalance the bridge, causing line failure or just a really hard to cross bridge.
• WATER: The wires are heavy-duty plastic and steel composites that are coated with material to give the spider traction when building. However, this only works to a point and excessive water could cause the spider to lose it's grip when building, or the team to slip while crossing.
• TEMPERATURE: The abovementioned coating will start to become sticky and gooey at high temperatures, making it very hard for the spider to build bridges correctly.
• CMTs: Snip=end of team. Although trying to shoot the wires is downright tricky from any distance, they're about as thick as a fist.

Part 4: Abuse

• The bridge is very carefully engineered, and cannot survive any lose of support due to a foundation being destroyed or line being cut. One snip and the whole thing will likely collapse.
• Yes, a troublehooter could laser-sight somebody's head and the spider will launch a plasma-cutter-tipped harpoon into it without any pause. This should be obvious to anyone who sees the demonstration of the bot in R&D.
• The bot has a limited self-preservation system, meaning that if it's damaged, it'll try to get back to R&D. If it falls, it will harpoon the nearest wall to try and stop.
• The bot is not armored in any way. It isn't designed to go into especially hostile terrain (heat, radiation, EMI, ETC) and it won't resist more than a blaster-shot or two.
• The laser sighting system is fairly powerful (for range and locating purposes) so a troubleshooter could probably blind someone with it.