Although many British loaves, especially in the last 30 years, have become simple doughs that take no more than an hour or two to make, there are more lengthy processes that still find favour particularly because they allow time for the wheaty taste to develop, and for as little yeast as possible to be used - both economical and good for long-keeping.
One of those methods is called the Scottish sponge, because a runny sponge was made the night before which acted as a ferment for the whole dough. These loaves are made according to that system. They are baked together in a block, though not in the same tin. You will find that packing them close together in the oven encourages high rise, and sometimes a wild movement towards each other.