On-demand ferry Me-Mel in Sydney's Bays Precinct

Few tasks in ferry planning are more difficult - or more important - than fleet planning.

If you want maximum flexibility in crewing, training and assignment across routes, the fleet would comprise a single vessel class. Having one class also makes the maintenance task simpler and less costly.

But having one class is not an option for Sydney, where the range of operating conditions call for at least three different types of boat -  one that can cope with big swells in the outer harbour; a smaller, nimble one running at mainly low speeds in the inner harbour; and another with shallow draft and moderate speed (up to 20 knots) on the Parramatta River.

There is also the problem of the legacy fleet where many of the existing vessels are not yet at the end of their economic life. They may not be exactly the sort of boats you now need, but it is not a commercial proposition to replace them immediately.

Planning in a Changing Environment

You have to play a long game in Sydney, envisioning what you would like the fleet to look like in 20 or 30 years when it is eventually possible to transition away from the legacy fleet. That long view needs to deal flexibly with changing demand and have an eye to advances in marine technology.

Due to three converging circumstances, now is a good time to develop such a plan.

• The current Freshwater Class Manly ferries are reaching the end of      their economic life. This milestone is fast approaching as it becomes      obvious that the competition - the smaller capacity catamaran class      operated by the Manly Fast Ferry company - is the sort of boat that's      better suited for this corridor, when operating at high frequency.

• Renewal of the ferry terminal at Circular Quay is also      imminent.  Retirement of the Freshwater Class will free up berths in      a redeveloped Quay. Right now, two berths on Jetty 3 are allocated to the      special requirements of the Freshwaters and another on Jetty 2 is assigned      to the Manly Fast Ferry. Reducing the requirements for the Manly corridor      to two berths, or even one, would have a transformative, decluttering      effect.

• Technology in vessel propulsion is progressing rapidly. Norway,      which has one of the world's largest ferry fleets, will only operate electric      or hydrogen powered vessels from 2026. Electric vessels use lithium-ion      batteries which get "top up" charging when docking. They often      use automated docking technology to save time and reduce operating costs.      The technology is best suited to vessels on shorter runs and relatively      low speeds, and would be well suited to Sydney's Inner Harbour routes.

     A Fleet Replacement Plan

The coming together of these three events makes the optimal fleet replacement strategy reasonably clear and straight forward:

Outer Harbour

Co-inciding with Circular Quay's renewal, the Freshwater Class boats need to be retired and all services to Manly operated by a frequent fast ferry. The question is then by whom and using what boats? Manly Fast Ferry probably has capacity to expand its fleet and operate all Manly services. Equally, Transdev Sydney Ferries could do the job using the new outer harbour version of its Emerald Class boats, which are expected to enter service in 2020 or 2021.

I lean towards the Emerald boats as they offer more inside seating than the MFF vessels (a better experience in cold, wet weather). It would also allow Jetty 2 to be customised to loading Emerald Class vessels, whether operating to Manly or Watsons Bay. This would likely mean the acquistion of more outer harbour boats as headways will need to narrow to 10 minutes in the peaks and on week-ends, especially in summer.

Planning for Circular Quay should be on the basis of accommodating higher frequencies (7.5 or 6 minute headways) as a contingency against future demand growth.

Inner Harbour

Fleet replacement for the Inner Harbour is a longer term proposition. Transdev Sydney Ferries intend refitting the iconic, Alan Payne designed First Fleet Class boats to extend their lives by at least 10 years, but planning for their replacement should start now as the redevelopment of Circular Quay will have to accommodate whatever replaces them, even if that's 10, 15 or 20 years away.

The First Fleeters have a capacity for 400 passengers and operate with three crew. The replacement class does not need to be this big. Smaller vessels (say 200 capacity) with a crew of two will be far more efficient:

• some routes currently operated by First Fleeters (eg Double Bay and      Neutral Bay) never reach 50% capacity, even on peak runs.

• for other routes, like Taronga Zoo and Barangaroo, extra services can be scheduled to increase frequency where justified by demand.

The savings achieved by operating boats with two crew instead of three far exceeds the extra cost of operating more frequent services in peak demand periods. It can also mean that late evening services on the inner harbour could be made more frequent, with headways reducing from the currently unattractive 60 minutes to 30 minutes.

Another benefit of smaller boats is the reduced footprint at Circular Quay, with the potential to unload two vessels from the same side of a pontoon.

Further cost savings can be made by the new inner harbour boats using low emission, all electric propulsion. Maintenance costs would be cut and the passenger experience enhanced by the quiet operation of electric ferries.

Parramatta River

Transdev Sydney Ferries has already committed to acquiring ten new purpose built catamarans for the Parramatta River, replacing two HarbourCats and four SuperCats. Presumably the plan is for the RiverCats to be retained in the short term, before moving eventually to a single catamaran class for the River.

On demand servicesTransdev Sydney Ferries has already purchased a small 60 capacity catamaran to operate its trial on demand service in the inner harbour and plans to acquire two more. This is problematic as there is a distinct possibility that an on demand ferry will not be commercially sustainable. A vessel with two crew and a capacity of 60 (more realistically 40 in wet, cold conditions), is not easy to plug into the inner harbour fleet when all the other boats have a capacity of 200. The smaller boats will simply be too small for timetabled services.ConclusionNostalgia can be a powerful emotion, but it is a poor substitute for good policy. Just because past operations have featured big boats does not mean they are also the future. And the optimal future, providing higher frequency services at less cost to taxpayers, is this:

• Emerald Class catamarans operating fast ferry services to Manly and Watsons Bay;

• a transition away from the 400 capacity First Fleet class in the Inner Harbour to a 200 capacity, all electric catamaran with a crew of two;

• a single class of river catamarans for the Parramatta River.

If on-demand ferries prove sustainable, then the small 60 capacity waterbus recently acquired by Transdev Sydney Ferries will fit the bill for this purpose, but if on-demand does not get past the trial stage, then these cute little waterbuses may need to disappear along with the other retiring classes.