Roland Perry wrote:
In message , at 08:47:27 on Sun, 28 Sep
2014, tim..... remarked:
The extra train, new stations and
additional track will also need to be maintained.

Is that really a noticeable percentage of 28 million?

Why do you think this particular stretch of line will pay its
operating costs from revenue, when the system taken as a whole doesn't?

[Tube fares are about £1.6BN, operating costs about £2.4BN, capital
costs on top of that].

How does that answer my question?

It shows that the margin cost of operating the line could well be of the
same order of magnitude as the farebox. In other words, you are seriously
underestimating the additional cost of operating the trains.

TfL apparently expects a modest operational surplus, presumably because
this simple above-ground line is relatively cheap to operate compared to
the deep level Tubes. And I suppose many of the additional fares will be to
Zone 1, and therefore quite expensive.