Interoperability
We're getting a lot of complaints from commuters who were routed onto a coaster, but the theme park patrons who spent hours stuck on an intercity line are also not happy.
We're getting a lot of complaints from commuters who were routed onto a coaster, but the theme park patrons who spent hours stuck on an intercity line are also not happy.
Black Hat gives a presentation to Cueball and Hairbun in which he emphasizes the importance of interoperability and compatibility. These terms refer to designing systems in such a way that systems can work together and share assets or components without modification. The terms are most commonly used in information technology to refer to different systems using the same formatting standards and communication protocols to allow the systems to interface and files to be exchanged easily. The terms also apply to hardware systems, where different pieces of equipment might use standardized parts and dimensions to allow them to be integrated easily. Railroads are a common example of this principle, if different railway systems are built to different gauges (the distance between the tracks), then rolling stock from one railway can't travel on another without major modifications. Building railroads to common specifications means that they can connect to one another, and can share, exchange and purchase equipment without compatibility issues.
Black Hat points out that US rail systems predominantly use the standard gauge of 143.5cm (or the virtually identical 4 ft 8½ in, in the US), and associated subway systems and their cars are built to match this standard. This is a good example of interoperable systems. However, he also points out that roller coasters typically use a different gauge, presenting this as a problem, then goes on to state that his company has been retrofitting roller coasters to match railway gauge, and speaks ominously about "Phase 2". This suggests that he plans to either run railroad stock on roller coasters or use roller coaster cars on train tracks.
There are many reasons why this would be a bad idea. Even with identical gauges, roller coasters would not be able to run on train tracks, or vice versa. The tracks, wheels and how they interface would still be completely different. Trains and subways using sets of flanged steel wheels on top of the track, while coasters use polyurethane rollers above, below, and to the sides of the track. Roller coasters are generally not powered, being initially lifted by a chain and then running on gravity and inertia. Roller coasters aren't built for the kind of weight or size typical to train cars. Any attempt to connect the two systems would almost certainly not work, and if attempted, would cause all kinds of damage and danger, while offering no obvious benefits. Given Black Hat's nature, it's unlikely that this gives him any pause.
The audience responds that "maybe interoperability is actually bad". In fact, while interoperability can have major benefits in the right circumstances, there are many cases in which different systems should not be interfaced, and designing them to make such interfaces impossible is a good design principle. For example, electric systems that operate at different voltages might have differently designed plugs, to prevent accidentally plugging one into the other. In this case, even if it were possible to interface trains and roller coasters, it would be a terrible idea.
The title text suggests that Black Hat's company has 'successfully' interfaced the two systems, allowing cars from each to travel onto the other (presumably meaning that they've solved the many, many engineering problems involved). Predictably, this has resulted in no benefits and major problems. Commuters on trains find themselves unexpectedly on roller coasters, which would be jarring, frightening, and dangerous (even if the track holds up and the train doesn't derail, lack of safety restraints would send people flying around the train cars). This is in addition to the simple fact that people trying to get to a destination largely wouldn't want to be routed onto an amusement park ride instead. By contrast, roller coaster patrons, expecting an exciting ride, would instead find themselves routed to ordinary transit lines, presumably going to destinations that they hadn't planned. Hence, even in the best case scenario, this connection would mess with everyone's plans, which is presumably Black Hat's central intention.