An enclosure wouldn't be a bad idea. But they need support too. Their entire weight looks like it is being born by the cistern.
I would put two clips on each pipe on the loft floor, then at least one clip each on the vertical, then another one each on the horizontal part of the platform.
I would put two clips on each pipe on the loft floor, then at least one clip each on the vertical, then another one each on the horizontal part of the platform.