There is a critical period of a day or two when the youngsters are mature enough to come out of the nest and show themselves, but not old enough to fly. And this is when I set my camera up to take a few pictures.
The parent appears to feed the young without actually landing. She (or is it He?) darts in with a cargo of food held in her beak, rams a morsel down each of two or three throats while hovering at the nest and then is gone - all within less time than it takes to read this. Thus in the first set of pictures below which were taken without flash, the images of the parent bird are blurred. Then the last few pictures were taken with a flash which helps "freeze" the motion, and you can see the parent much better.
Here we see the four chicks anxiously awaiting the next food shipment. The mud nest was constructed where two metal re-inforcing bars cross between two of the beams that hold up the loft.
In the bottom right-hand corner of the above picture you can just see the blur of the parent arriving with food. The bright yellow-and-pink mouths of the chicks are all open wide, competing as beacons to attract the attention of the mother.
The parent prepares for in-flight docking with the first of the chicks.
Then she turns her attention to the second chick.
Here's a close-up of the process. She has not actually landed on the nest but appears to be steadying herself against it as she continues to hover with wings beating rapidly.
Having fed the second chick, she departs to collect another load of food.
Waiting in anticipation of the mother's arrival.
Here's one for you...
...and one for you...
and one for you.
Oh Come All Ye Faithfull...