History will eventually be the judge on whether the RCN's choice of design for the new Naval Large Tug [NLT] project is a correct one. I for one have some doubts.
The navy's requirements, re-stated simply were for a vessel that could carry out ship berthing in the naval dockyards, provide firefighting capability, perform coastal towing, and be of a proven commercial-type design. The last of those requirements seems a strange one to me, since no two tug operations are so similar that a design can be "proven" from one to another. Many tug operators are able to make a standard tug design work for them, but it can usually be shown that there could be improvements in one or more aspects of operation. As tug designs evolve progress is rarely made by standing still.
The four tug order will provide two tugs for HMC Dockyard in Halifax and two for HMCDY Esquimalt, in British Columbia. The difference in coastal towing alone from those two bases is so significant (open ocean from Halifax and sheltered inland waters of the Salish Sea in BC) certainly indicates to me that a "proven design" simply means a design that has already been built and used in a variety of operating conditions.
Over the forty plus years since the last RCN dockyard tugs were built most of the tug industry had settled on two engines driving stern mounted azimuthing thrusters (ASDs), with a small share of the market given over to true tractors - drives mounted forward, with azimuthing or cycloidal Voith Schneider (like the current Glen tugs) propulsors.
However in more recent times there have been an almost infinite variety of nuanced hull forms where azimuthing tugs can push, pull or tow with equal power from the same position. Enough of these have been built to justifiably make the claim for "proven."
Not only that but low emission engines have evolved too. In addition to the IMO Tier III standard, there have been numerous varieties of hydrids built using generators, electric motors and batteries to improve efficiency and reduce pollution. Several of these have passed the experimental stage and are arguably "proven". Dual fuel diesel / LNG ships have now become the norm for new vessel construction of tankers and ferries in Canada. They are still largely protoyypical for tugs.
According to a press release, the RCN has chosen a RAmparts 2400 design from Robert Allen Ltd of Vancouver. The pre-eminent tug designers in not just Canada, but the world, the Robert Allen firm has probably designed every variety of tug mentioned in the above paragraphs and more (including the three thruster ROTOR tugs) and even worked in concert with their prime competitor, Damen, the most prolific tug builder, on some of them. Certainly their portfolio of proven designs would be wide ranging. Why a shallow draft, harbour tug design, not normally fitted with a towing winch, was chosen in view of the above requirements is a mystery.
Not included in the press release was a detailed description of the propulsion system supplier. That the engines will be IMO Tier III goes without saying, but there is no mention of how the fire pumps will be powered, how the stern drives will be energized, etc., nor what company will provide the system. Since engines are at least as important as all the rest of the tug, this is a critical piece of information, currently lacking. The standard RAMparts 2400 has a strictly conventional diesel / shaft / thruster arrangement.
Industrie Océan has built many tugs of different sizes - some simple and some complex - and has worked closely with Robert Allen, and Damen too.
What I am getting around too is that both designer and builder are capable of producing just about any kind of tug you could throw at them.
It is therefore puzzling that the RCN has chosen the RAmparts 2400 series. This is a basic, some would say traditional, budget tug, (48 have been built world wide, with more on the boards). They have been used in many different situations, including for the US Navy, but with no obvious suitability to the RCN's special requirements.
My opinion is that the RCN has several fairly unique requirements that need to be taken into account:
1. Tight spaces and light displacements. The Halifax dockyard features very narrow cambers between finger piers, where relatively light displacement warships tie up. This means that tugs do not have much room to manoeuvre. Once tethered to a ship they should be able to work without shifting position. While ASD tugs can do this to a degree they are not ideal. Tractor types are better. (The current Glens can often be seen working stern forward - living proof that the tractor is the answer, but that a better hull design is needed.).
The light displacement ships do not require high bollard pull tugs, but they also need precise control over power. Certainly the infinitely variable cycloidal systems are superior in these cases. However they have other limiations. True tractors with controllable pitch props, and/or ASDs with electric drives with various power options (main engine, auxiliary engine, battery and combination) would be the most efficient and effective.
A lot of the jobs Dockyard tugs do is shifting scows, placing fenders, and don't inlvove large ships. Again the low power engine option is ideal in these situations.
At only 24m long the RAmparts 2400 is obviously designed for tight spaces, because it is short. That would certainly indicate limitations on sea keeping for coastal towing.
The standard propulsion package answers none of the efficiency or environmental issues.
2. Occasional larger ships. The new tugs will eventually be tasked with berthing heavy displacement supply ships and icebreakers, so sometimes will need more power. Again the propulsion system with a variety of power sources is the logical choice for operational cost and emission control. Short trips between piers or where no towing or pushing powers is required is common for most tugs and certainly true for these tugs. Again a propulsion system that allows for low power drive is called for, with full power needed for only short periods of time. Only then are the main engines needed, when they can be run at peak efficiency.
3. Fire fighting. While required to provide fire protection in the Dockyards, this is so seldom needed that it can probably be accommodated by means of a PTO from one of the main engines, or from the central power sharing hub, rather than a dedicated auxiliary engine. The space (and cost) saved could certainly be utilized for battery space or even LNG fuel storage.
4. Ocean towing. Is this still a requirement for these tugs, not a just a 'nice to have'? Most ASD tugs that do both harbour berthing and towing are fitted with two (very expensive) winches - one forward and one aft - each equipped with different ropes/wires to suit the purpose. However there are now designs (that are proven) where a single double drum unit can be used. The hull design needed for such an installation is not the RAStar 2400. In fact I would say that the coastal towing requirement has been dropped, since only towing bits or hook are provided. This is a missed opportunity.
[There is a valid argument I suppose that coastal towing is not needed - the Kingston class MCDVs are on the way out and they have been the most often towed away for refits. Halifax tugs have towed these ships as far as St.John's. NL.]
5. Submarine berthing. RCN tugs in Halifax at least, are just as likely to have to berth US Navy subs as they are RCN subs, so underwater fendering will be a necessary feature of the new tugs. I do not know how this will be addressed. Protecting sub hulls from ASD thrusters could present a challenge.
6. Ice class. No mention has been made as to ice class for these tugs that I have heard. Although it is probably not a high priority (most of the RCN does not want to be anywhere near ice). A case can be made for this requirement, but within the tugs' life times there maybe no ice left. The Swedish navy has just taken delivery of some ice class tugs for example, but they are on the Baltic where it is essential.
7. Why navy tugs at all (a.) and why only four (b.) ? Part a. of the question has been thrashed out, but I thought the reason the navy opted to buy their own rather than hire in, was that they had unique requirements that could only be met with their own design. To my mind the standard RA2400 spec could be met by most of the commercial tug operators in eastern Canada on a moment's notice.
The other, and more cogent argument is that the navy and its pilots do things differently from civilians, and that only dockyard based tugs (and crews) should be used. I buy this, but not on the basis of operating costs or tug design.
As to why only four - certainly a mistake. Halifax has three Glen class tugs now and no dedicated fire tug. Having only two NLT's does not allow for refits or extended times away from port while towing.
With the Halifax based navy fleet increasing by four (larger) ships over the next few years, having only two NLTs seems short sighted. For example what if a there is a fire on a ship in the Dockyard? One NLT is fighting the fire and there is not enough remaining tug capability to move other ships out of the way. Or what if one tug is away for refit? Commercial tugs will be brought in,and if they can do the job in a pinch, why can't they do it all time?
It also reflects poorly on part a. because the navy will have to hire commercial tugs either for the coastal towing or for harbour work or in case of emergency.
I grant I may be jumping the gun on several of the above issues for want of more detailed information. However I think the navy, using the same team of designers and builders, could have done better. If these tugs are expected to give 30 or 40 years of service they should be at the very least state of the art now. They should also be capable of adopting newer technologies later in their service lives, and should be as "green" as possible.
My particular concerns are certainly environmental, but cost and operaiotnal eeffectivenss are important too. I hope to hear better information that I have now.
Most of the world's RAmparts 2400s have been built in Turkey. They are constructed as day boats, but sleeping accommodation for crew can be added if desired.
Some have been built with full crew quarters, but they do not have towing winches:
I am certainly not implying that the RAmparts 2400 design is inferior. What I am saying is that either the RCN's requirements have changed (no coastal towing) or that they trying to use a proven design for a general purpose harbour tug when what they should be building is something quite different. Maybe they will a get a very nice horse when what they really need is a camel.