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::''This is a Draft article''

An '''Anti-Torpedo Net''' (sometimes "Torpedo Net") is a heavy metal mesh intended to block and stop torpedoes.

They came in two basic forms:  ship's nets which could be deployed from a ship on metal booms that swung out from the beam, and harbour defence nets which were generally suspended from floats to guard ships at anchor within a port.

Nets and torpedoes (with or without cutters affixed) were a game of Rock, Paper, Scissors with probabilistic outcomes.

==British Experience==

===Trials===
In 1915 and 1916, the British conducted extensive tests of their own torpedo nets,{{ARTS1915|pp. 62-65, ''Annual Report of the Torpedo School, 1916'', pp. 60-66}} firing their own torpedoes at them fitted with a variety of [[Net Cutter|net cutters]].  This augmented their battle experience where they could see how their nets fared when German torpedoes and cutters were fired against them.

In 1916, the latest British ship's net was the "Type Pa".  It was noted that it was about as effective as the earlier "Type G", and was presently vulnerable to "[our] own torpedoes and pioneers."  Their harbour net model at the same time was "Type R", and was currently proving 75% effective by the Fiume net cutter (a type the Germans were known to have at least evaluated) on 3 out of 12 tests in 1916.  Whether or not the Germans were using the Fiume net cutter, the British knew that the Germans regarded their cutter as being able to defeat any known net if it struck it at a speed over 5 knots.

Lacking further insights into the cutters the Germans were actually using, the British set out to develop a net that could reliably thwart the Fiume net cutter, and declared success in this regard by developing the "Type T" harbour net during 1916.

{|border=1
!Type of Net||Torpedo||Speed<br>knots||Cutter||No.<br>Trials||No.<br>Penetrated||Penetration<br>Rate
|-
|R||18-in Mark VII||41 ?||Fiume||1||1||100%
|-
|RU||18-in R.G.F. Mark VII||41||Fiume||5||1||20%
|-
|RU||21-in Mark II***||45||E 1||2||0
|-
|T||18-in Mark VII||41||Fiume||5||0
|-
|T||21-in Mark II***||45||Fiume||1||0
|-
|S||18-in Mark VII||41||Fiume||2||0
|-
|S||21-in Mark II***||33||Fiume||1||0
|-
|TL||18-in Mark VIII*||41||Fiume||3||0
|-
|TL||18-in Mark VII||41||Fiume||3||0
|-
|TL||21-in Mark II***||45||Fiume||2||0
|-
|TE||18-in Mark VIII*||41||Fiume||5||0
|-
|TE||18-in Mark VII||41||Fiume||1||0
|-
|TE||21-in Mark II||45||E 2||8||3||38%
|-
|Pa||18-in Mark VIII-VIII*||41||E 2<br>fixed blades "B"||1||0
|-
|Pa||18-in Mark VIII-VIII*||29||E 1<br>sliding blades||3||0
|-
|Pa||18-in Mark VIII-VIII*||41||E 1<br>sliding blades||3||1||20%<ref>May have exploited previous net damage.</ref>
|-
|Pa||18-in Mark VIII-VIII*||41||E 1<br>existing pattern<br>sliding blades||6||3||50%
|-
|Pa||18-in Mark VIII-VIII*||41||18-in pattern<br>w/ strengthening shoes||4||2||50%
|-
|Pa||21-in Mark II***||45||Hardy||1||0
|-
|Pa||18-in Mark VIII-VIII*||41||Hardy||15||3||20%
|-
|S||21-in Mark II***||29||Spearhead<br>4 bladed||1||0
|-
|Pa||21-in Mark II***||29||Spearhead<br>4 bladed||1||0
|-
|Pa||21-in Mark II***||45||Spearhead<br>2 bladed||1||1||100%
|-
|TL||21-in Mark II***||45||Spearhead<br>2 bladed||1||0
|}

{{TBCTONE}} more trials from ARTS 1916, p66

===Conclusions===
The British had come, by 1916, to regard their "Type T" net as generally effective in harbours, but problematic for use as a ship's net unless it was to defend a bombarding ship, as the nets were found to slow and render un-handy the ships while under way.  Their hope was in passive defence in hull design, and they expressed optimism that void spaces able to vent to the atmosphere when struck by a torpedo may prove promising.

{{TBCTONE}}

==See Also==
* [[Net Cutter]]

==Footnotes==
{{reflist}}

==Bibliography==
{{refbegin}}
*{{ARTS1915}}
*{{ARTS1916}}
*{{ARTS1917}}
*{{ARTS1918}}
{{refend}}

[[Category:Shipboard Equipment]]