SM U-99

{{Infobox ship image

|Ship image=

|Ship caption=

}}

{{Infobox ship career

|Hide header=

|Ship country=German Empire

|Ship flag={{Shipboxflag|German Empire|naval}}

|Ship name=U-99

|Ship ordered=15 September 1915

|Ship builder=AG Weser, Bremen

|Ship yard number=250

|Ship laid down=30 November 1915

|Ship launched=27 January 1917

|Ship commissioned=28 March 1917

|Ship fate=Missing after 7 July 1917

|Ship homeport=

}}

{{Infobox ship characteristics

|Hide header=

|Header caption={{sfn|Gröner|1991|pp=12-14}}

|Ship class=German Type U 57 submarine

|Ship displacement=

{{convert|750|t|LT|abbr=on|lk=on}} surfaced
{{convert|952|t|LT|abbr=on}} submerged

|Ship length=

{{convert|67.60|m|ftin|abbr=on}} (o/a)
{{convert|54.02|m|ftin|abbr=on}} (pressure hull)

|Ship beam=

{{convert|6.32|m|ftin|abbr=on}} (o/a)
{{convert|4.05|m|ftin|abbr=on}} (pressure hull)

|Ship height={{convert|8.25|m|ftin|abbr=on}}

|Ship draught={{convert|3.65|m|ft|0|abbr=on}}

|Ship power=

2 × {{convert|2400|PS|kW shp|abbr=on|lk=on|0}} surfaced
2 × {{convert|1200|PS|kW shp|abbr=on|0}} submerged

|Ship propulsion=2 shafts, 2 × {{convert|1.65|m|ftin|abbr=on}} propellers

|Ship speed=

{{convert|16.5|kn|lk=in}} surfaced
{{convert|8.8|kn}} submerged

|Ship range=

{{convert|10100|nmi|abbr=on|lk=in}} at {{convert|8|kn}} surfaced
{{convert|45|nmi|abbr=on}} at {{convert|5|kn}} submerged

|Ship test depth={{convert|50|m|ft|abbr=on}}

|Ship complement=4 officers, 32 enlisted

|Ship armament=

4 × {{convert|50|cm|in|1|abbr=on}} torpedo tubes (two bow, two stern)
10–12 torpedoes
1 × 8.8 cm SK L/30 naval gun deck gun

|Ship notes=

}}

{{Infobox service record

|is_ship=yes

|is_multi=yes

|partof=

II Flotilla
7 June – 7 July 1917

|commanders=

Kptlt. Max Eltester{{cite Uboat.net

|id=65

|name=Max Eltester

|type=1comm

|accessdate=16 March 2015

}}

28 March – 7 July 1917

|operations=1 patrol

|victories=None

}}

SM U-99{{#tag:ref|"SM" stands for "Seiner Majestät" ({{langx|en|His Majesty's}}) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.|group=Note}} was one of the 329 submarines serving in the Imperial German Navy in World War I.

U-99 was engaged in the naval warfare and took part in the First Battle of the Atlantic.{{cite Uboat.net

|id=99

|name=U 99

|type=1sub

|accessdate=16 March 2015

}}

Design

U-99 had a displacement of {{convert|750|t|LT}} when at the surface and {{convert|952|t|LT}} while submerged.{{sfn|Gröner|1991|pp=12-14}} She had a total length of {{convert|67.60|m|ftin|abbr=on}}, a pressure hull length of {{convert|54.02|m|ftin|abbr=on}}, a beam of {{convert|6.32|m|ftin|abbr=on}}, a height of {{convert|8.25|m|ftin|abbr=on}}, and a draught of {{convert|3.65|m|ftin|abbr=on}}. The submarine was powered by two {{convert|2400|PS|kW shp}} engines for use while surfaced, and two {{convert|1200|PS|kW shp}} engines for use while submerged. She had two propeller shafts. She was capable of operating at depths of up to {{convert|50|m}}.{{sfn|Gröner|1991|pp=12-14}}

The submarine had a maximum surface speed of {{convert|16.5|kn}} and a maximum submerged speed of {{convert|8.8|kn}}.{{sfn|Gröner|1991|pp=12-14}} When submerged, she could operate for {{convert|45|nmi}} at {{convert|5|kn}}; when surfaced, she could travel {{convert|10100|nmi}} at {{convert|8|kn}}. U-99 was fitted with six {{convert|50|cm}} torpedo tubes (four at the bow and two at the stern), twelve to sixteen torpedoes, and one 10.5 cm SK L/45 naval gun deck gun. She had a complement of thirty-six (thirty-two crew members and four officers).{{sfn|Gröner|1991|pp=12-14}}

Fate

U-99 sailed on 12 June 1917 with further contact after 13 June; she went missing after 7 July.

=Previously recorded fate=

U-99 was thought to have been sunk by British submarine {{HMS|J2}}, but the attack was conducted at extreme range and is unlikely to have accounted for U-99.