Coding classes in Essex

Start with the run. 1.33 miles at 8 miles an hour takes 9.98 minutes; at 10 miles an hour it takes 7.98. So a train leaving the shore on the hour reaches the Pier Head somewhere between 8 and 10 minutes past, which leaves it 5 to 7 minutes before the published quarter-past departure back. It reaches the shore again between 23 and 25 past, and waits 5 to 7 minutes for the half-hour departure. One train, going back and forth, can work the whole published timetable. We are not saying how many trains the pier actually uses; we are saying what the arithmetic requires.

The last row is the one that surprises people. The difference between 8 and 10 miles an hour looks small, but at a ten-minute headway it decides whether the service needs two trains or three, because the round trip at 8 miles an hour is just over twenty minutes once each end has its turnaround. Fleet size jumps in whole trains, so a small change in speed can cost a large change in equipment. Every bus company, airline and delivery firm meets this staircase.

Now the single track. With two trains, one leaving each end at the same moment, they meet after 4.43 minutes. If both run at the same speed they meet exactly in the middle of the pier, which is where a passing place would sit. But if one runs at 10 miles an hour and the other at 8, the meeting point moves 119 metres from the middle towards the slower train's end. A passing place cannot move, so the faster train arrives first and waits, about a minute. Delay on a single track is not caused only by breakdowns; it comes from two trains that are each running perfectly well at slightly different speeds.

So an Essex teenager should learn to program in 2026 not to compete with machines at writing lists, but to be able to tell a workable plan from a tidy impossible one. The longer argument is in why teenagers should still learn to code in 2026.