The more I look at it I think it might be a 132kV line on a 400kV tower, with the intention to upgrade it some time in the future. I say this because the insulators aren’t actually the full length of the spacing from the tower, there’s a separator between the tower and the start of the insulator fins. This makes me think they’ve left room for longer 400kV insulators to be installed.

Saying that though I have no idea, there could have been all sorts of other considerations that led to a configuration like that.