MTB Vosper

This page is about the British motor torpedo boat MTB Vosper. For other versions, see MTB Vosper (Family).

MTB Vosper

HMS Leopard

MTB Vosper(2)

MTB Vosper

HMS Leopard

MTB Vosper(2)

Britain

I Rank

Battle rating:

AB	RB	SB
1.0	1.0	1.0

Class:

Motor torpedo boat

Boat

Research:2 900

Purchase:700

Show in game

Description

The MTB Vosper 1 series is a rank I British motor torpedo boat with a battle rating of 1.0 (AB/RB/SB). It was introduced in Update 1.83 "Masters of the Sea" as part of the British fleet closed beta test. With the split of the naval tech trees in Update "New Power", MTB Vosper was moved to the coastal fleet tech tree.

General info

Survivability and armour

Armourfront / side / back

Hull24 mm (wood)

Superstructure15 mm (wood)

Number of section3

Displacement38 t

Crew10 people

MTB Vosper internals (starboard). Note the ammunition storage below the bridge.

Vosper 1 series has the following armour layout:

• Hull: 24 mm, wood
• Superstructure: 15 mm, wood

Any gun in the game will easily be able to penetrate the hull and superstructure at any practical range.

The hull is split into three compartments. The first compartment starts at the bow and ends in front of the bridge; the second ends behind the aft gun mounts, just after the fuel tanks; and the third ends at the stern. Vosper 1 series can be hull-broken by any round with a large enough diameter and explosive mass. In general, this is limited to HE rounds greater with a diameter greater than or equal to 4 inches (102 mm) with an explosive mass greater than 1.5 kg. At Vosper 1 series' battle rating, there is no gun capable of hull-breaking her.

There is one ammunition storage that holds ammunition for all gun mounts. It is located directly below the bridge, just above the waterline. Destroying it will instantly destroy the boat.

Vosper 1 series has a crew complement of 10. With a stock crew, it is knocked out when 6 crew are lost; with an aced crew, this is increased to 7. Overall, the survivability is average.

Mobility

Speedforward / back

AB104 / 36 km/h

RB74 / 26 km/h

Mobility Characteristics
Game Mode	Upgrade Status	Maximum Speed (km/h)		Turn Time (s)	Turn Radius (m)
		Forward	Reverse
AB	Stock	76	27	~19.42	~37.78
	Upgraded	104	36	~12.61	~23.97
RB/SB	Stock	64	22	~21.92	~43.61
	Upgraded	74	26	~17.83	~34.68

Vosper 1 series has a displacement of 38 tons.

When moving forwards at high speeds, the bow will drift slightly to starboard without any player input. When moving backwards, the bow drifts slightly to port.

Modifications and economy

Repair costBasic → Reference

AB79 → 97

RB119 → 146

Total cost of modifications2 960

900

Talisman cost190

Crew training200

Experts1 000

Aces20

Research Aces96 000

Reward for battleAB / RB / SB

10 / 20 / 100 %

100 / 100 / 100 %

Modifications

Seakeeping	Unsinkability	Firepower
Dry-Docking Research: 200 Cost: 60 50 Rudder Replacement Research: 165 Cost: 50 40 Propeller Replacement Research: 370 Cost: 110 95 Engine Maintenance Research: 240 Cost: 75 60	Damage Control Division Research: 200 Cost: 60 50 Fire Division Research: 165 Cost: 50 40 Smokescreen Research: 165 Cost: 50 40 New Pumps Research: 240 Cost: 75 60	7.7 mm AP belt Research: 200 Cost: 60 50 7_7mm_lewis_navy_incendiary_ammo_pack Research: 165 Cost: 50 40 Primary Armament Targeting Research: 370 Cost: 110 95 Artillery Support Research: 240 Cost: 75 60 Torpedo Mode Research: 240 Cost: 75 60

The recommended modification research order is:

1. Tool Set
2. Fire Protection System
3. 7.7 mm AP belt
4. Smokescreen
5. Propeller Replacement
6. Artillery Support

After that, prioritize the rest of the seakeeping modifications first, then research the remaining modifications in whatever order you prefer.

Armament

Primary armament

4 х Turret2 x 7.72 mm Lewis machinegun 1916

Ammunition1940 rounds

Belt capacity97 rounds

Fire rate551 shots/min

MTB Vosper gun turret placements. The two mounts behind the bridge are staggered to not obstruct each other when firing to the sides.

The primary armament consists of eight 7.72 mm Lewis 1916 machineguns in four twin mounts. Two of these are mounted side-by-side in front of the bridge with the other two staggered behind the bridge. There are 1,940 rounds of ammunition available for each mount, 970 rounds per gun, for a total of 7,760 rounds. Stock, the mounts can traverse horizontally and vertically at a rate of 64°/s; with the "Primary Armament Targeting" modification installed, this is increased to 75°/s. Each gun has a magazine capacity of 97 rounds and a cyclic rate of fire of around 550 rounds/min. With a stock crew, the guns can be reloaded in 10.4 seconds; with an aced crew, they can be reloaded in 8 seconds.

Turrets are named sequentially, clockwise, starting at the bow

Primary armament guidance
No.1 Turret (fore-starboard)		No.2 Turret (aft-starboard)		No.3 Turret (aft-port)		No.4 Turret (fore-port)
Horizontal	Vertical	Horizontal	Vertical	Horizontal	Vertical	Horizontal	Vertical
±180°	-7°/+70°	±180°	-10°/+70°	±180°	-10°/+70°	±180°	-7°/+70°

There are three ammunition types available:

• Universal: AP · T · AP · T

• 7.7 mm AP belt: AP · AP · AP · T

• 7.7 mm API belt: IT · IT · IT · AP

Penetration statistics
Ammunition	Penetration @ 0° Angle of Attack (mm)
	10 m	100 m	500 m	1,000 m	1,500 m	2,000 m
Universal	10	9	8	7	6	5
7.7 mm AP belt	10	9	8	7	6	5
7.7 mm API belt	10	9	8	7	6	5

Within all of the belts, the AP round is the main damage dealer. The T round deals very little damage to both surface targets and aircraft, only really being useful as a guide for aiming. As a result, the AP belt, with its 3:1 ratio of AP:T rounds, is the most effective in all situations. The Universal belt, with its 1:1 ratio of AP:T rounds, is a direct downgrade from the AP belt in terms of damage and should be replaced by the AP belt as soon as it's unlocked. While the API belt, comprising wholly of IT rounds, may initially seem like the best option due to the incendiary effect of the IT rounds, the IT round in practice is actually comparable to the T round in damage, rarely starting fires and doing incredibly little damage against surface targets. Against aircraft, the difference in damage between the AP belt and the API belt is negligible.

Additional armament

Setup 12 x 533 mm Mk.VIII torpedo

Vosper 1 series has two possible loadouts:

1. 2x Mk.VIII torpedo
2. Without load

Torpedoes

Vosper 1 series can carry two 533 mm Mk.VIII torpedoes. The torpedo tubes are located on either side of the bridge, pointing forwards with the nose angled outwards.

Torpedo characteristics
Torpedo Mode	Mass (kg)	Maximum speed in water (km/h)	Travel distance (km)	Depth stroke (m)	Arming distance (m)	Explosive type	Explosive mass (kg)	TNT equivalent (kg)
No	1,566	84	4.57	1	50	TNT	327	327
Yes	1,566	76	6.40	1	50	TNT	327	327

The Torpedo Mode modification is available as a rank IV modification. Installing it will give the following changes:

Torpedo mode specification changes
Max Distance (m)	Max Speed (m/s)
+1,830	-2

It's best to always keep Torpedo Mode uninstalled. The maximum speed of a torpedo is much more valuable in coastal battles than its maximum range. Coastal fleet maps are also small enough that the decreased range with Torpedo Mode installed isn't much of an issue.

In RB, always set the depth stroke to the minimum 1 m setting. This is because many vessels that MTB-1 1 series can face will not have a deep enough draught to fuse the torpedo at a depth stroke setting of 4 m. In AB, depth stroke is automatically set to the most optimal setting.

When using torpedoes, be aware that unless they are already launched, the torpedoes have a very high chance to detonate when shot at, instantly destroying the boat. To avoid this, fire the torpedoes immediately after spawning in—as well as after any subsequent reloads in AB—or simply don't take them at all. Torpedoes are a situational weapon, so it's largely down to personal preference whether or not to take them.

Usage in battles

In terms of armament, Vosper 1 series is very similar to the reserve vessel of the tech tree, MTB-1(1), the difference being in the placement of the guns. While MTB-1 1 series has the eight guns split into two quadruple mounts, Vosper 1 series has them in four twin mounts. With this arrangement, Vosper 1 series can typically only bring four or six of her eight guns on target at once, since the mounts block each other at most angles. Although there is a small ~7.5° arc about 60° to port (between the 9 and 10 o'clock positions) where all eight guns can be used at once, it's difficult to keep targets in such a small range, so this shouldn't be relied on. Because of this, Vosper 1 series is limited to only a fraction of the firepower of MTB-1 1 series, whose armament wasn't very good to begin with. That said, this gun arrangement does come with a few benefits, the most significant of which being the much quicker reloads, nearly half of that of MTB-1 1 series. Additionally, having twin mounts instead of quad mounts also makes each individual mount smaller, reducing the likelihood of losing a turret to random fire and making it less detrimental should it happen.

Even with these differences, though, Vosper 1 series has nearly the exact same playstyle as MTB-1 1 series due to the limitations of the guns. Because of their bad damage output, always keep enemies in directions where six of the guns can fire. Similarly, because of their poor ballistic qualities, stick to close-range engagements and avoid open areas of the map wherever possible. Make use of Vosper 1 series' higher top speed to rush into ambush positions behind cover that MTB-1 1 series would be too slow to reach. From there, support your team by targeting distracted enemies. For larger opponents such as sub-chasers, try not to draw attention to yourself with gunfire. Instead, either use the torpedoes, or simply mark them on the map for your team, call artillery, and then retreat behind cover.

Despite the reloads being shorter than that of MTB-1 1 series, they are still quite long overall, so it's still a good idea to be proactive with the reloads. Always be aware of how much ammunition is left in the guns and fire off any remaining ammunition if there isn't much left after engagements, retreating to do so if necessary. Like MTB-1 1 series, a good time to do this with Vosper 1 series is when the magazines are about half empty, though it may not always be obvious when that is just from the ammunition counter, since not all of the guns can fire at once. The guns can only sustain fire for about 10 seconds before needing to reload, so make use of that to determine the amount of remaining ammunition by mentally keeping track of how long you've fired the guns. Lastly, like MTB-1 1 series, it should be noted that Vosper 1 series can only carry enough ammunition for ten reloads at most, though again just like MTB-1 1 series, Vosper 1 series also doesn't tend to survive long enough for this to become an issue, so keep that in mind but don't worry too much about it.

Pros and cons

Pros:

• Good manoeuvrability
• Good torpedoes: above-average maximum speed and explosive mass

Cons:

• Primary armament consists only of low-calibre machineguns: very low overall damage output
• Not all gun mounts can be brought on target at once, one or more of the turrets will be blocked at most angles

History

During the 1930s, the Admiralty began to reestablish the coastal boat flotillas it once commanded during the First World War. British boatbuilding company Vosper & Company competed for the contract but lost both times in 1935 and 1936, the lucrative contract to build the first coastal boats since WWI going instead to their rival, British Power Boat Company. In response to this, Vospers developed plans for a faster and more seaworthy design than that of their rivals'. In the following months, Vospers proposed their new design to the Admiralty multiple times, but ultimately, they could not secure a contract to build a prototype. Around this time, though, the Admiralty officials had unofficially suggested that future contracts would only be awarded for vessels that could surpass 40 knots in speed and that were armed with two 21-inch torpedoes as well as an assortment of light anti-aircraft guns. Additionally, it was known from previous specifications that the Admiralty wanted a vessel capable of operating in open waters in at least Force 5 winds and that was fast enough to cross the English Channel during the night. With these unofficial specifications, Vospers preemptively began development on a new vessel as a private venture at the company's own expense.

Immediately, it was decided that the private venture vessel had to be larger than the existing 60 ft British Power Boat MTB in order to meet the specifications. Additionally, engines more powerful than the Napier Sea Lion engines used in the BPB design were required. With none available domestically, Vospers looked to the Asso 1000 engine by Italian manufacturer Isotta-Fraschini. Though in limited supply, the Asso 1000 was specifically designed for marine craft and provided the necessary power: 1150 bhp at 1500 rpm maximum and 950 bhp at 1660 rpm continuous. In late 1936, Vospers completed their design. It called for three Asso 1000 engines and two in-house 75 bhp auxiliary engines, the latter of which could be coupled to the outer shafts to give a total maximum power of 3600 bhp. The hull-form was a hard chine planing design and was 69½ ft in length with a displacement of about 33 tons. The prototype was laid down before the end of the year and completed in May 1937.

Upon completion, the prototype underwent internal trials where she achieved a top speed of 47.8 knots unloaded and 43.7 knots loaded. Satisfied with these results, Vospers presented the prototype to the Admiralty for official trials against the 60 ft British Power Boat MTB. The prototype fared favorably, and after much deliberation, the Admiralty decided to purchase the vessel from Vospers. She was commissioned in May 1938 as MTB 102 and sent to HMS Vernon for further evaluation. Up to this point, MTB 102 had not actually been fitted with torpedoes, so during her time at HMS Vernon, many torpedo configurations were tested. These included the tried-and-true yet outdated stern projection systems, as seen on the 60 ft British Power Boat MTB and earlier WWI designs, as well as a unique arrangement of a single launcher in the stem of the hull with a reload carried internally. These all had their own issues, and none were found to be satisfactory. Ultimately, it was decided that MTB 102 should have two torpedo tubes mounted on either side of the bridge, pointed forwards with the nose angled outwards, an uncommon configuration for the time. Around this time, the gun armament had also not yet been decided, so various configurations were also experimented with, including combinations of 0.303 in and 0.50 in machine guns and a 20 mm autocannon.

Impressed with MTB 102, the Admiralty placed an order for four more vessels on 15th August 1938, Vospers' first-ever Admiralty contract. These vessels, and any ordered after, all shared the same overall design as MTB 102, although with several minor changes such as the hull being lengthened to 70 ft 3¼ in. After 1940, with the entrance of Italy into the war, Isotta-Fraschini engines could no longer be obtained, and subsequent boats had to be fitted with much weaker American Hall Scott engines—only 1800 bhp total—as a stopgap measure until they could be upgraded with more powerful Packard engines, although this wasn't until 1941 as supply was limited. Of the 32 planned 70 ft Vosper MTBs, 28 were completed and are as follows:

• MTBs 20-23: Ordered 15th August 1938, all were completed by December 1939. MTBs 20, 21, and 23 were sold to the Romanian Navy. MTB 22 served with the 4th MTB Flotilla. She survived to the end of the war and was sold in 1945.

• MTBs 29-30: Ordered on 8th September 1938—including a Thornycroft design, MTB 28—as replacements for the three boats sold to Romania, all were completed by July 1940. Both MTB 29 and 30 served with the 4th MTB Flotilla. MTB 29 was lost in a collision with a German E-boat on 6th October 1942, and MTB 30 struck a mine and was lost on 18th December 1942.

• MTBs 31-40: Ordered on 27th September 1939, six were completed by May 1941. MTBs 33, 37, 39, and 40 were bombed by German aircraft while under construction in 1940-41. The completed boats survived to the end of the war and were sold in 1945-46.

• MTBs 57-66: Ordered on 26th February 1940, all were completed by April 1942. MTB 61 was stranded during an attack on 9th May 1943, and MTBs 63 and 64 were lost after collisions with friendly MTBs on 2nd April 1943. The remaining boats were sold in 1944.

• MTBs 69-70: Ordered in April 1940, both were completed by June 1940 and received only two engines. Both were stationed at HMS Beehive, Felixstowe. They both survived to the end of the war and were sold in 1945-46.

• MTBs 218-221: Ordered on 7th December 1940, all were completed by September 1941. MTB 218 struck a mine and was lost on 18th August 1942, and MTB 220 was sunk by German E-boats on 13th May 1942. MTBs 219 and 221 survived to the end of the war. MTB 221 was sold in 1945, and MTB 219 was transferred to the Sea Cadet Corps at Staines in 1945 and was converted to a houseboat in 1948.

The 70 ft Vosper MTB design continued to receive many improvements and modifications order-to-order and would lead to the development of the 72 ft Vosper MTB and 73 ft Vosper MTB.

Media

Skins

• Skins and camouflages for the MTB Vosper from live.warthunder.com.

See also

• MTB Vosper (Family)
• MTB Vosper(2)
• GIS 811
• MTB-1(1)

External links

• [Coastal Forces Veterans] Boat Database
• [ww2ships.com] 70' Vosper Motor Torpedo Boat
• [Unit Histories] Royal Navy Coastal Forces 1940-1945
• [naval-history.net] British vessels lost at sea in World War 2 - MGB, MTB, SGB, ML, etc - originally published in British Vessels Lost at Sea, 1935-45, His Majesty's Stationary Office, 1947

Bibliography

• Lambert, J., & Ross, A. (1993). Allied Coastal Forces of World War II Volume II: Vosper MTBs & U.S. Elcos (pp. 21-32). London, England: Conway Maritime Press. ISBN 0-85177-602-7.