#3097: Bridge Types

XKCD comic, described below.
Transcript

Bridge Types

[A 4x4 matrix of 16 ways to cross the same rectangular hole in the ground]

Plank [A plank laid over the hole, with Cueball standing on the left side of the plank, just past the edge of the hole.]

Rope [A rope bridge with rope guardrail. Cueball is standing in the middle, causing the bridge to sag about one Cueball-length down.]

Truss [A truss bridge with a triangular truss above the bridge deck. Cueball is visible in the center of the third truss from the left.]

Trestle [A trestle bridge, slightly higher than the edges of the hole, with small ramps at either end. Cueball is standing about a third of the way from the left.]

Arch [A straight deck, supported by what looks like three stone or brick arches. Cueball is notably absent.]

Suspended Arch [A single large arch spanning the entire gap, with the bridge deck suspended from the arch by nine support cables. Cueball is standing approximately in the middle, between the fourth and fifth cables from the left.]

Draw [A truss bridge split into two parts, the right half supported by a single straight pillar in the hole and the left half being pulled upwards by a large winch. One Cueball is standing on the outermost part of the left half and another is standing on the innermost part of the right half, directly over the pillar.]

Suspension [A bridge deck supported by cables hung from two pillars and going to the edges of the hole, with smaller cables linking those to the deck. Cueball is standing just left of center on the bridge.]

Filler [The hole is filled with rocks, which are larger than Cueball at the bottom but diminish in size the further up they are. Cueball is standing a third of the way from the left edge of the hole.]

Budget Overrun [A bridge deck suspended from a single pillar that starts in the bottom left corner of the hole, then angles to the right such that the top of it is above the middle of the deck. Nine support cables are visible, but another one is likely behind the pillar itself. Cueball is standing between the thoitd and fourth cables from the right.]

Jump [Ramps are present on both sides of the hole. Cueball, riding a skateboard, is in the air approximately a third of the way from the left, indicating that he has jumped off of the left ramp.]

Halfhearted [A simple bridge deck, sagging so much that the majority of it is on the floor of the hole. Cueball is standing in the hole, about two-fifths of the way from the left.]

Waterbed [The hole is now full of water, with two fish and an octopus visible in the water. Two Cueballs are crossing, and seem to be struggling to maintain their balance as the bridge warps and undulates under their feet.]

L'Engle [There is no bridge; instead, the terrain itself is warped such that the top corners appear to be pulled together to join in the center, with arrows illustrating their movement, although there is still a void in the lower center of the hole. Cueball is hopping from the left protrusion to the right.]

Fun [The bridge does a rollercoaster-style loop in the center. The entirety of the bridge is supported by vertical struts. Cueball, on a skateboard, is halfway to the top of the loop.]

Repurposed Elevator [Instead of a bridge, there is an elevator tower rotated on its side, with 7 evenly spaced exits. One Cueball is standing to the left of the elevator tower, one Cueball is on top of it and appears to be hugging it, and one Cueball is in the elevator carriage on the "seventh floor," on the right side of the hole.]


(Sourced from explainxkcd.com)

Title text:Pontoon bridges are just linear open-sided waterbeds.


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