Engineering notes · 11
Practical writing on sizing, stabilization and distribution — the three decisions that decide whether the television works after the vessel leaves port.
Commissioning starts with a drilling drawing. What must be true before the ACU is energised, what a tracking test proves, and what the handover file needs.
The drilling drawing is the one document that turns an antenna order into a deck modification. Read it in the right order and the yard gets it right first time.
A micro-cell layer inside the hull only works if there is something to re-broadcast. The outdoor antenna is part of the indoor design — range included.
One has capital cost and no airtime; the other has airtime and no line-of-sight need. The comparison is about where the vessel works, not price.
A deck camera rarely fails — its window does. Salt film, funnel soot and wipe marks are three problems, and only one is solved by a wiper.
The terminal supports all three bands. The operator, the route and the weather decide — and getting it wrong costs in a way the hardware never shows.
Buying the next model up is not only a gain decision. It is 12 to 93 kg more weight, a taller radome, and a different conversation with whoever owns the mast.
The marking is a string, not a badge: Ex d IIC T6 Gb for gas, Ex tD A21 for dust. What each part means, and what the string does not tell you.
Buyers size a TVRO antenna by physical diameter. The number that decides whether the picture holds is minimum EIRP — and it moves the other way.
The third axis is not a marketing upgrade. It changes what the antenna holds when the hull heels and yaws together — and whether your route needs it.
The antenna gets the satellite. The distribution layer decides whether anyone can watch it — and whether you can ever add VOD, CCTV channels or per-cabin menus.