The two breast shot water wheels operate trip hammers.
No1 hammer incorporates a wooden spring beam. When a cam lobe on the cam drum lifts the hammer, it must also bend the spring beam. On release, gravity and strain energy both contribute to the hammer blow. An enormous, oak drome beam holds the structure together and damps vibration which would shake the hammer apart.
No2 hammer is heavier and has been carefully designed so that the sweet spot of the hammer falls within the anvil face. Thus reaction forces at the pivot are eliminated.