46 CFR 144.920: Window and portlight strength requirements
Last reviewed: October 14, 2026
This section sets strength and safety rules for windows and portlights. Each window or portlight and its attachment must withstand the maximum expected load from wind and waves. Coverings over a window or porthole that could be a means of escape must open from within, and glazing in windows of a new towing vessel must not break into dangerous fragments.
Applies toParagraphs (a) and (b) are not limited to new vessels in the text, and paragraph (c) applies to windows of a new towing vessel.
What it says
Each window or portlight, and its means of attachment to the hull or the deckhouse, must be capable of withstanding the maximum expected load from wind and waves, due to its location on the vessel and the vessel's authorized route.
46 CFR 144.920(a)“must be capable of withstanding the maximum expected load from wind and waves, due to its location on the vessel and the vessel's authorized route.”
Any covering or protection placed over a window or porthole that could be used as a means of escape must be able to be readily removed or opened from within the space.
46 CFR 144.920(b)“Any covering or protection placed over a window or porthole that could be used as a means of escape must be able to be readily removed or opened from within the space.”
Glass and other glazing materials used in windows of a new towing vessel must be materials that will not break into dangerous fragments if fractured.
46 CFR 144.920(c)“Glass and other glazing materials used in windows of a new towing vessel must be materials that will not break into dangerous fragments if fractured.”
Common questions
How strong must a window or portlight be?
Each window or portlight and its means of attachment to the hull or the deckhouse must be capable of withstanding the maximum expected load from wind and waves. The load depends on its location on the vessel and the vessel's authorized route.
“must be capable of withstanding the maximum expected load from wind and waves, due to its location on the vessel and the vessel's authorized route.”
Can a cover over a window that could be used for escape be fixed shut?
No. A covering or protection placed over a window or porthole that could be used as a means of escape must be able to be readily removed or opened from within the space.
“Any covering or protection placed over a window or porthole that could be used as a means of escape must be able to be readily removed or opened from within the space.”
What glazing material is required in windows of a new towing vessel?
Glass and other glazing materials used in windows of a new towing vessel must be materials that will not break into dangerous fragments if fractured.
“Glass and other glazing materials used in windows of a new towing vessel must be materials that will not break into dangerous fragments if fractured.”
The text of 46 CFR 144.920
Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR
Window or portlight strength in a new vessel
(a) Each window or portlight, and its means of attachment to the hull or the deckhouse, must be capable of withstanding the maximum expected load from wind and waves, due to its location on the vessel and the vessel's authorized route.
(b) Any covering or protection placed over a window or porthole that could be used as a means of escape must be able to be readily removed or opened from within the space.
(c) Glass and other glazing materials used in windows of a new towing vessel must be materials that will not break into dangerous fragments if fractured.
The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.