Technological Disjunctures and the 21st Century Icebreaker
2017-03-27 By Danny Lam
Polar Ice Breaking is the epitome of industrial age technology. Traditional icebreakers is about the application of brute force and power to “break” through sea ice by powering through or up to 21ft in thickness by ramming. A physical process that is well understood, with decades of experience for the needed physical force and durability required in a icebreaker platform.
Icebreakers routinely places extreme stresses on hulls and systems, and rely on high safety margins (or overengineered) structures to withstand the stress or to rely on fail safe features like double hulls. Even then, it is not enough and a significant cost of operating icebreakers is on board damage control and repair capabilities. Repair shops aboard adds to crew and facility requirements, further reducing “payload” on a given sized platform.
Consequently, icebreakers are historically costly to build, operate, and own, and governments recoil at the cost when a single heavy polar icebreaker (PIB) easily cost $1 billion.
The 21st Century, however, offers the opportunity to accomplish the mission more economically with information age technologies. Since the 1980s, commercial aircraft have employed sophisticated software, sensors for “Flight Envelope Protection”. Pilots “fly-by-wire” through software that have different modes (Flight Control Laws) optimized for different situations that prevents overstressing the airframe.
Similar operational software can be created for an icebreaker that dynamically integrate data on sea ice conditions, optimal route pathways with input from off platform sensors like UAVs, and simultaneously, minimize unnecessary stresses on the hull and risks: Ice “Break Envelope Protection”, (BEP) is a feasible concept today.
However, Ice Break Envelope Protection technology has been slow in coming to the naval architecture community.
It is technically feasible to install a dense system of sensors to measure the forces on the PIB’s hull and systems (like propellers) in real time, and to do what is now routinely done for civilian aircraft: software that ensure the vessel is operated within design and safety limits.
Something as simple as a sensor that detects excess ice and momentarily slow the propeller to reduce damage.
Automatic tracking of cumulative stresses and cycles will improve maintenance, and ultimately, enable lighter, less overengineered structures to be built. Integrating this system with a “look ahead” sensor system that predicts stresses from different ice formations ahead will automate and improve a process that presently rely solely on the skills, experience and expertise of the crew.
The Operational Requirement Document (Nov 2015, Industry Version) for the USCG icebreaker did not specify a requirement for a web of sensors that collect, analyze, and archive data for the PIB, nor did it suggest the use of software based “Break Envelope Protection”.
Adding this feature will only marginally add to the cost of the program and offer the potential to lower operating costs (e.g. by predicting and avoiding damage) and substantially improve on future Icebreaker designs. In due course, the acquisition of this data will ultimately enable each class of icebreakers to perform above their present limitations.
Alternatively, BEP software offer the prospect of upgrading existing no-ice capable vessels like the DDG-51 to operate as light icebreakers.
PIBs are expected to have a life of 30 years. It is a foregone conclusion that in that time, substantial changes in the IT environment will have occurred. Ease of upgradability is a long term performance enhancer that impact on almost every aspect of suitability requirements. 4.1.3 Reference this issue and specify open architecture and modularity. Prematurely stipulating modules may hinder designs, but by not specifying existing candidates may result in “one off” modules being proposed.
Pre-existing efforts at modularization such as the Electronics Modular Enclosure (EME) used in the Zumwalt Class, LCS Mission modules or StanFlex need to be evaluated. Even if it is deemed unsuitable, economies can be realized without adopting existing modules simply by retaining existing form factors and interfaces for the modules.
Likewise, provisions for future installation of a small, 4 cell VLS like the Mark 57 launcher that mounts on the side of the hull can be considered. VLS launchers can have many non-military applications such as launching UUV or UAVs delivered by rocket (a Russian innovation), or heft microsatellites into orbit.
Many of these applications are just beginning to be recognized. Or, they can be armed as required.
Rather than operating alone, future icebreakers will be tightly integrated into a web of space, aerial and other sensors and have a degree of situational awareness that is unimaginable as recently as the 1970s.
The USCG Polar Icebreaker Requirements (March 18, 2017) recognize that unmanned vehicles will play an increasing role (2.13.15) beyond the UAVs presently used for scouting routes. Unmanned platforms, particularly UUVs, will likely play a far greater role in the future as reliable high bandwidth communications with lasers make it feasible to operate a fleet of UUVs.
UUVs are ideally suited to scout out routes in pack ice, where, the proverbial iceberg is 90% below surface.
Other missions, like monitoring fisheries, detection of intruders and mine warfare and to requirements.
Thus, the ability to rapidly deploy, recover, and sustain unmanned platforms under all conditions may be a major consideration.
Requirement 2.13.15 at present stipulate UUVs to be launched and recovered from the deck. This is a task that can be hampered by ice.
What about capability to operate UUVs from a “Moon pool” or other below surface (and ice) system?
Finally, there is the question of propulsion.
If an electric propulsor design is chosen, it opens a discussion as to how best to supply the electrical power: conventional gas turbines or diesels, or potentially a modest nuclear reactor?
Much of the complexity and maintenance issues of nuclear powered vessels arise from the use of nuclear-steam turbines directly driving a propeller and the need to throttle power.
Once the decision is made to go “electrical”, energy storage can smooth out peaks and valleys and enable the power plant (whether conventional or nuclear) to be operated at close to its optimal.
Thus, it may be worthwhile to revisit the feasibility of nuclear power for its many advantages.