Orla and Ciara are very fast twin engined ships used mainly in the inshore areas. However, when manoeuvering in harbour, these ships use an electro-hydraulic propellor clearly shown between both shafts, one main prop and the much smaller auxillary.driven engine for low speeds. The power of the main engines does not allow such delicacy even at idle speeds. Interestingly the "harbour manoeuvering" engine is retracted into the hull when the main engines are in use in order to reduce drag.
This photograph was taken when LE Emer was in Verolme Docktard's dry dock undergoing annual overhaul.