Infrastructure You Walk Past

Questions

1. 1
   Not answered. This ridged grey canister is mounted on a wooden utility pole, wired into the overhead line above it. What is its main electrical job?
2. 2
   Not answered. Two similar ribbed devices hang from the crossarm above this transformer, each wired into the incoming line — a lightning (surge) arrester and a fuse cutout. What is the real functional difference between them?
3. 3
   Not answered. This green metal cabinet sits on a concrete pad at ground level in a yard, with warning labels and a locked door. What does it most likely contain?
4. 4
   Not answered. A long chain of stacked ceramic discs hangs from this transmission tower's crossarm down to the conductor. Why are so many discs strung together instead of using one long insulator?
5. 5
   Not answered. A small device shaped like two weighted dumbbells joined by a short flexible cable is clamped onto this overhead line, away from any tower. What problem is it solving?
6. 6
   Not answered. A small bright orange spinning disc is clipped onto this overhead line, well away from any tower or insulator. What is it there to do?
7. 7
   Not answered. A small dark egg-shaped fitting is spliced into this taut steel guy wire, well above ground level. Why is it there?
8. 8
   Not answered. The overhead wires strung between these poles visibly droop between supports rather than running perfectly straight. Why do utilities deliberately let them sag like this?
9. 9
   Not answered. A small printed tag is fixed to this utility pole at about head height. Which of these are typical reasons utility poles carry an identification tag like this?
10. 10
    Not answered. This cluster of flat rectangular panels is mounted near the top of a building, each panel bolted to face a different horizontal direction. What are they doing?
11. 11
    Not answered. Two large horn- or drum-shaped metal reflectors sit near the top of this tower, angled outward in different directions rather than pointing straight up. What is their job?
12. 12
    Not answered. A compact set of antennas is bolted partway up this ordinary street lamppost, well below the height of a typical cell tower. Which of these are real reasons mobile carriers deploy small cells like this instead of relying only on tall towers?
13. 13
    Not answered. A black ribbed cylindrical case is mounted on this wall, with several thin cables entering one end and a loop of slack cable coiled beside it. What is inside the case, and why is cable coiled up next to it rather than pulled tight?
14. 14
    Not answered. This fire hydrant's body is painted red and its bonnet and caps are painted white. In the U.S. hydrant color-coding scheme (NFPA 291), what does the cap color usually tell a firefighter?
15. 15
    Not answered. This brass assembly of two shutoff valves and a smaller relief valve is installed on a building's water supply pipe, just after it enters from the street. What is it protecting against?
16. 16
    Not answered. This fenced facility, full of parallel valves, filters, and pipework connected to buried gas mains on both sides, sits at a neighborhood's edge. What is its main job?
17. 17
    Not answered. This short white post, labeled "GAS PIPELINE" with an identifying code, stands alone in the grass with no other visible pipework nearby. What does it connect to underground, and what is it for?
18. 18
    Not answered. The test post is wired to the buried pipeline, which is in turn wired to a separate buried block of a more reactive metal, commonly zinc or magnesium, some distance away. Which of these statements about that setup are correct?
19. 19
    Not answered. This oval cast-metal cover, embossed with the maker's name and an animal emblem, sits flush with the sidewalk. Why is that information cast directly into the metal instead of printed or painted on?
20. 20
    Not answered. A stenciled marker beside this street-level grate reads "No Dumping — Drains to Ocean." Which of these statements about storm drains and sanitary sewers are correct?
21. 21
    Not answered. This heavy iron manhole cover is round rather than square or rectangular. Which of these are genuine engineering reasons manhole covers are commonly made round?
22. 22
    Not answered. This cast-iron pipe rises vertically from the ground beside a building, stamped with a foundry's name, with no fixtures or faucets attached to it anywhere. What is its purpose?
23. 23
    Not answered. Two shallow parallel cuts run across this traffic lane near the stop line, each filled with a rubbery sealant tracing a rectangular outline in the asphalt. What is buried in that cut, and how does it detect a car?
24. 24
    Not answered. This grey roadside cabinet, opened up, is packed with electronic modules, wiring, and a small keypad and display panel. Which of these are things a traffic signal controller cabinet typically contains or does?
25. 25
    Not answered. This shaped, energy-absorbing metal head caps the very start of a highway guardrail, angled slightly away from the roadway rather than pointing straight at oncoming traffic. What is it engineered to do if a vehicle hits it head-on?
26. 26
    Not answered. On this older stretch of guardrail, the rail's end simply curves downward and buries itself in the ground rather than ending in a shaped crash head. Why have transportation agencies moved away from this "turned-down" design?
27. 27
    Not answered. This gap at the base of the curb, leading into an underground drain, is noticeably wide and set low rather than being a small grated hole in the road surface. What does that shape and placement mainly optimize for?
28. 28
    Not answered. This white dome-shaped marker is set into the road surface between lanes, reflecting light back toward an approaching driver's headlights. What is the common English name for this general class of raised, retroreflective road marker — a category that includes the glass "cat's eye" invented in the UK by Percy Shaw in 1934?
29. 29
    Not answered. This round cast-iron manhole cover, of a common heavy-duty street type, sits flush with the road surface. Roughly how many kilograms does a cover like this typically weigh?