Background: one could say naval ops in cold weather environment in Northern latitudes. With many Western naval capabilities depending on the use of vessel-based aerial platforms the combat performance of surface units declines sharply once the aerial platforms can’t fly. Also sensor performance (radar) sharply once the vessel starts jumping around in heavy seas, possibly making targeting difficult (and that does not even take into account sensor performance degradation in snow and ice storm and spray filled seas).
Does anyone have hard facts concerning the various environmental limits for flight operations on the various classes of ships? Sea states, ice build-up, etc. Even CVN can jump around too much in high waves for flight ops (not even talking safe flight ops), and once the deck is icing up from the spray in higher sea states taxiing becomes impossible on those steel decks (since they are not heated). Are there any doctrines taking that into account?
There are of course limits for high sea water temperatures for heat-exchangers upon ships, especially critical for nuclear powered units. Any info there?
Also not aviation related: The doors of the VLS cells. Where they ever tested with ice build-up? There are pictures from Murmansk convoys, and also from Kriegsmarine units with heave ice build-up all over the ship. Are those doors heated?
Excellent topic. Clearly, it is not just environmental factors (notably wave height, wind) but also ship design (as this impacts not only how lively a particular shipdesign may be but also e.g. where the helicopter deck is relative to the water surface i.e. “freeboard”)
Destroyers and their aviation detachment crews fleetwide have been trained on using the OPPs.
“Operator polar plots” (OPP) consist of a series of placard overlays that identify limits and safety considerations that take into account a ship’s speed and sea conditions in addition to pitch, roll and relative winds. Based on the height and direction of waves, a specific OPP is used by both the ship’s officer of the deck and the helicopter pilot to determine the best options for safely landing a helicopter on a ship’s flight deck.
“This was a joint effort across several commands,” said Capt. Jack Olive, responsible for aviation operations aboard surface ships for Commander Naval Surface Force, U.S. Pacific Fleet. “Naval Sea Systems Command, Naval Air Systems Command, Naval Air Forces, Navy Safety Center and Naval Surface Forces worked together to address the safety concerns of landing helicopters on low freeboard flight decks, such as destroyers.”
A low freeboard flight deck is one that is close enough to the surface of the water such that a wave could wash over the flight deck, creating a hazardous situation for crew and equipment. Olive noted that Arleigh Burke-class destroyers have a flight deck approximately 13 feet above the waterline.
“Because the deck is so close to the waterline, conditions could exist that allow waves to more readily come over the deck,” Olive said.
OPPs are placards that officers of the deck use to plot the ship’s heading and speed, with overlays designed for certain sea states to determine limits for safe handling during flight operations. The direction of waves relative to the ship heading and ship speed are also marked on the placard. This plotted point will exist somewhere on the graph and if a given condition (denoted by different colors and crosshatch marks) indicate potentially risky or dangerous conditions, the ship can take actions, such as adjusting ship’s course and speed, to mitigate those conditions.
Ship speed is shown in five-knot increments on concentric circles from the center of a graph, with waves shown relative to the ship’s position. Red and yellow areas are speed-heading combinations to be avoided. Regions defined by dark lines with cross hatching reflect areas where launch and recovery roll and pitch limits may be exceeded.
http://www.navy.mil/submit/display.asp?story_id=85891
Related story: http://www.militarytimes.com/story/military/2015/06/28/lawrence-helicopter-tragedy-accident-ddg-investigation-hazrep/29162991/
You may find Part E, Chapter 1, Section 1of “Rules for the classification of ships” of interest. http://www.veristar.com/portal/veristarinfo/detail/generalinfo/giRulesRegulations/bvRules/navalrules
See also http://www.rina.org/en/our-services/classification/naval-ship-services
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