This is an old series parellel bank; notice how each transformer feeds one hot leg on the secondary. (120 from each TR instead of 240/120) There are still many of these banks around almost all consisting of 2-25 KVA's used in place of a single 50 KVA. (I did see one once using two 100's to create a 200 KVA 120/240 service to an apartment high-rise). Each transformer has to be set to put all the capacity out of one bushing simular to if they were serving in a 208/120 bank.