feel free to jump in and help arrange the vocabulary below in alphabetical order :)
使用试验 utility test
有效寿命 useful life
向上焊接 upward welding
向上通风 upward ventilation
上游设计 upstream design
倾覆力矩 upsetting moment
倾覆力臂 upsetting arm (or lever)
直立艏柱 upright stem
正浮位置 upright position
立式钻床 upright drill (or drill press)
顶上横帆 upper top gallant sail
上层桥艛 upper bridge
舵承上部 upper bearer
向上冲程 up stroke
低适航性 unseaworthiness
无人载具 unmanned vehicle
万向接头 universal joint
接合螺帽 union nut
潜弧焊接 union melt welding
活管套节 union
均匀强度 uniform strength
匀布负荷 uniform load
等速流动 uniform flow
单流驱气 uniflow scavenge
单向引擎 uniflow engine
单向纱束 unidirectional roving
单向天线 unidirectional antenna
水下防护 underwater protection
海底管路 underwater pipeline
水下检查 underwater inspection
海底电缆 underwater cable
水中声学 underwater acoustics
水中焊接 under water welding
潜航阻力 under water resistance
水下滑道 under water launching ways
水下装具 under water fittings
水中切割 under water cutting
不足膨胀 under expansion
不平衡舵 unbalanced rudder
不均衡力 unbalanced force
伞形天线 umbrella antenna
超级油轮 ultra large crude oil carrier (ULCC)
极限应力 ultimate stress
极限强度 ultimate strength
舱壁甲板 ulkhead deck
载货吨 useful (or cargo) dead weight
咖啡壶 urn
小便池 urinal
倾覆点 upsetting point
倾覆角 upsetting angle
顶横帆 upper topsail
舵头材 upper stock
上甲板 upper deck
白麻绳 untarred rope
裸甲板 unsheathed deck
管套节 union piece
不顺整 unfairness
潜水舰 underwater craft
航行灯 under way lamp
卸压载 unballast
紫外线 ultra-violet
超短波 ultra-short wave
液面计 ullage stick
液面计 ullage scale
液面孔 ullage hole
潜水艇 U-boat
器具 utensil
烟道 uptake
倾覆 upset
卸货 unload
出坞 undock (or undocking)
航行 under way
美国标准学会 USASI (or ASA, or ANSU) (= United States of America Standards Institute, U.S.A.)
使用性能试验 usability test
端压对头焊接 upset butt welding
万能螺旋扳手 universal screw wrench
万向窝座关节 universal and socket joint
单柱塞喷射泵 unit pump (or single plunger unit pump)
个别给水系统 unit feed system
泡沫塑料芯材 unicellular foamed plastic cores
超音波测厚器 ultrasonic thickness indicator
超音波探伤器 ultra-sonic detector
极限浸水强度 ultimate wet strength
极限抗拉强度 ultimate tensile strength
轴承极限能力 ultimate bearing capacity
国际铁道联盟 UIC (= International Union of Railways)
美国海岸防卫队 USCG (= U.S. Coast Guards, U.S.A.)
最上层全通甲板 uppermost continuous deck
不饱和聚酯树脂 unsaturated polyester resin
双吊杆操作系统 union purchase system
独立细孔泡沫胶 unicellular foam
意大利标准协会 UNI (= Unificazione, Italy)
西班牙国家标准 UNE (= Una Norma Espanola, Spain)
上甲板以下吨位 under upper deck tonnage
无阻尼自然频率 undamped natural frequency
油面深度容积表 ullage table
超音波试验 UT (= ultrasonic testing)
超浅吃水船 USDV (= ultra shallow draught vessel)
烟道通风筒 uptake ventilator
杆端锻粗机 upsetting machine
弯部上缘 upper turn of bilge
上甲板吨位 upper deck tonnage
水在线船体 upper (or dead) works
不稳定平衡 unstable equilibrium
无人化机舱 unmanned machinery space
万能试验机 universal testing machine
万向导索器 universal fairlead (or fairleader)
万向联结器 universal coupling
活管套接头 union joint
整流冷凝器 uniflux condenser
水下下水台 underwater launching way
海底研究船 undersea research vehicle
悬吊平衡舵 underhung balanced rudder
甲板下通路 underdeck passage (or way)
焊珠底龟裂 underbead crack
过饱和蒸汽 under-cooled (or supersatuated) steam
水下计程仪 under water log
低电压电驿 under voltage relay
甲板下吨位 under deck tonnage
无阻尼振动 undamped vibration
超音波检查 ultrasonic inspection
超浅吃水船 ultra shallow draught vessel (USDV)
油面测距孔 ullage port (oil tank)
液面测距孔 ullage port
液面测距板 ullage board