?匀布负荷    uniform load

?均匀强度    uniform strength

?活管套节    union

?活管套接头    union joint

?潜弧焊接    union melt welding

?接合螺帽    union nut

?管套节    union piece

?双吊杆操作系统    union purchase system

?乌拉圭技术标准学会    UNIT (= Institute Uruguayo de Normas Technicas, Uruguay)

?单元组合,小组合    unit assembly

?装单元组合安装    unit assembly and installation of auxiliary

?个别给水系统    unit feed system

?单柱塞喷射泵    unit pump (or single plunger unit pump)

?万向窝座关节    universal and socket joint

?万向联结器    universal coupling

?万向导索器    universal fairlead (or fairleader)

?万向接头    universal joint

?万能螺旋扳手    universal screw wrench

?万能试验机    universal testing machine

?卸货    unload

?卸货装置,抑压器(压缩机)    unloader

?无人化机舱    unmanned machinery space

?无人载具    unmanned vehicle

?无阻横摇,自由横摇    unresisted rolling

?不饱和聚酯树脂    unsaturated polyester resin

?低适航性    unseaworthiness

?裸甲板    unsheathed deck

?不稳定平衡    unstable equilibrium

?白麻绳    untarred rope

?升流管集箱,升流管头箱    up cast header

?向上冲程    up stroke

?水在线船体    upper (or dead) works

?舵承上部    upper bearer

?上层桥艛    upper bridge

?上甲板    upper deck

?上甲板吨位    upper deck tonnage

?上旁频带(电)    upper side-band

?舵头材    upper stock

?顶上横帆    upper top gallant sail

?顶横帆    upper topsail

?弯部上缘    upper turn of bilge

?上甲板间[空间]    upper tween deck