Difference between revisions of "MGB-75"

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(Anti-aircraft armament: Updated to 2.5)
(Additional armament: Expanded on depth charges)
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{| class="wikitable" style="text-align:center" width="65%"
 
{| class="wikitable" style="text-align:center" width="65%"
! colspan="8" | '''Guidance for the Anti-Aircraft Gun Turrets'''
+
! colspan="8" | Anti-aircraft armament guidance
 
|-
 
|-
 
! colspan="2" rowspan="1" | No.1 Turret (starboard)
 
! colspan="2" rowspan="1" | No.1 Turret (starboard)
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{{main|Mk.VII depth charge}}
 
{{main|Mk.VII depth charge}}
  
[[File:MGB-75_DCs.png|thumb|Mk.VII depth charges numbered 1-2 according to their drop order (click to expand).]]
+
MGB-75 has two possible loadouts:
  
MGB-75 can carry two Mk.VII depth charges mounted amidships, one on each side in front of the twin 7.72 mm Lewis machinegun 1916 mounts facing outwards. The depth charges are dropped one at a time in this order (see the image):
+
# Without load
 +
# 2x Mk.VII depth charge
  
# Starboard side
+
'''Depth charges'''
# Portside
+
 
 +
[[File:MGB-75_DCs.png|thumb|Mk.VII depth charges numbered according to their drop order (click to expand).]]
 +
 
 +
The Mk.VII depth charges are carried amidships, one on either side of the bridge next to the twin 7.72 mm Lewis 1916 machine guns. They are dropped one at a time in the following order:
 +
 
 +
# Starboard
 +
# Port
  
 
Before spawning, the detonation time delay can be set anywhere between 3 seconds and 10 seconds.
 
Before spawning, the detonation time delay can be set anywhere between 3 seconds and 10 seconds.
 
 
{| class="wikitable" style="text-align:center"
 
{| class="wikitable" style="text-align:center"
! colspan="4" | '''Depth Charge Characteristics'''
+
! colspan="7" | Depth charge characteristics
 
|-
 
|-
 
! Mass (kg)
 
! Mass (kg)
! Explosive Type
+
! Explosive type
! Explosive Mass (kg)
+
! Explosive mass (kg)
! TNT Equivalent (kg)
+
! TNT equivalent (kg)
 +
! HE armour penetration (mm)
 +
! Armoured vehicle destruction radius (m)
 +
! Fragment dispersion radius (m)
 +
|-
 +
| 196 || TNT || 130 || 130 || 101 || 8 || 122
 
|-
 
|-
| 196 || TNT || 130 || 130
 
 
|}
 
|}
 +
 +
There is almost no practical reason to use depth charges on any naval vessel in the game. Although they usually result in a one-hit kill if used properly, they are extremely situational, requiring the player to close to point-blank ranges to even use them. In almost every case, anytime a depth charge could be used, the guns can be used instead to greater effect. In fact, depth charges tend to actually be a liability in battle, since they essentially act as exposed ammo racks before they're dropped. They can be shot at, and if destroyed, they have a chance to detonate, instantly destroying the boat.
 +
 +
Despite this, some success can be had in dropping them either next to, or in front of a large, slow target. If dropping them next to the target, remember the depth charge drop order, since it's most likely that only the depth charges dropped on the side closest to the enemy will deal any damage. If dropping in front of the target, rush in from the sides as quickly as possible and drop them all at once directly in front of the target. For both cases, set the depth charge time delay to the minimum 3 seconds, since any higher time delay will only allow the depth charge to sink further away from the target, giving them more time to move out of the way. Again, using depth charges is extremely situational, and they will only be a liability the vast majority of the time, so take them at your own discretion.
  
 
== Usage in battles ==
 
== Usage in battles ==

Revision as of 10:23, 31 May 2021

Rank VI USSR | Premium | Golden Eagles
Su-25K Pack
MGB-75
uk_71ft_mgb.png
GarageImage MGB-75.jpg
MGB-75
Purchase:1 000 Specs-Card-Eagle.png
Show in game

Description

The 71 ft MGB-75 is a premium rank II British motor gun boat with a battle rating of 2.0 (AB) and 2.3 (RB/SB). It was introduced in Update 1.91 "Night Vision". Originally a rank I vessel, with the split of the naval tech trees in Update "New Power", MGB-75 was moved to rank II in the coastal fleet tech tree.

General info

Survivability and armour

Armourfront / side / back
Hull40 mm (wood)
Superstructure15 mm (wood)
Number of section3
Displacement52 t
Crew12 people

MGB-75 has the following armour layout:

MGB-75 internals (starboard side).

Like most coastal vessels, MGB-75 has no practical armour. The gunshields are largely superficial; while they may stop low-calibre machine guns, heavy machine guns and cannons will easily penetrate them at any range. The hull and superstructure are unarmoured and will not stop any sort of gunfire.

The hull is split into three hull sections. Starting from the bow and working towards the stern, the first section starts at the bow and ends just in front of forward gun; the second ends after the bridge, forward of the engines; and the third ends at the stern.

Any round with a large enough diameter and explosive mass can hull break MGB-75. In general, this is limited to HE rounds with a diameter greater than 4 inches (102 mm) and with an explosive mass greater than 1.5 kg. At MGB-75's battle rating, the only guns that can hull break her are:

There are two ammunition storages. The first ammunition storage, which holds ammunition for the primary armament, is located in the hull above the waterline, below and slightly in front of the forward gun turret. The second ammunition storage, which holds ammunition for both the secondary and AA armament, is located above deck, in front of the aft gun turret. Destroying either will instantly destroy MGB-75. Since it is located above deck, the second ammunition storage is particularly susceptible to detonation by random gunfire or artillery.

MGB-75 has a crew complement of 12. With a stock crew, MGB-75 is knocked out when 8 crew are lost; with an aced crew, this is increased to 9. Overall, survivability is below-average.

Mobility

Speedforward / back
AB104 / 29 km/h
RB78 / 22 km/h
Mobility Characteristics
Game Mode Upgrade Status Maximum Speed (km/h) Turn Time (s) Turn Radius (m)
Forward Reverse
AB Stock 77 21 ~29.18 ~55.47
Upgraded 104 29 ~19.63 ~34.71
RB/SB Stock 67 19 ~32.4 ~64.46
Upgraded 78 22 ~26.3 ~50

When moving forwards at high speeds, the bow will lift out of the water. This creates a blind spot where the 40 mm 2pdr QF Mk.IIc is unable to depress far enough to hit the waterline in an area ~400 m in front of the boat.

MGB-75 has a displacement of 51.5 tons.

Modifications and economy

Repair cost
AB465 Sl icon.png
RB683 Sl icon.png
Crew training4 800 Sl icon.png
Experts32 000 Sl icon.png
Aces250 Ge icon.png
Research Aces440 000 Rp icon.png
Reward for battleAB / RB / SB
Talisman.png 2 × 70 / 80 / 50 % Sl icon.png
Talisman.png 2 × 124 / 124 / 124 % Rp icon.png
Modifications
Seakeeping Unsinkability Firepower
Mods new ship hull.png
Dry-Docking
Mods new ship rudder.png
Rudder Replacement
Mods new ship screw.png
Propeller Replacement
Mods new ship engine.png
Engine Maintenance
Mods ship damage control crew.png
Damage Control Division
Mods ship fire control crew.png
Fire Division
Mods engine smoke screen system.png
Smokescreen
Mods new ship pumps.png
New Pumps
Mods new aa caliber turrets.png
Anti-Air Armament Targeting
Mods ammo.png
40mm_qf_mkxv_he_ammo_pack
Mods ammo.png
20 mm HE magazines
Mod arrow 0.png
Mods new aux caliber turrets.png
Auxiliary Armament Targeting
Mods ammo.png
40mm_qf_mkxv_ap_ammo_pack
Mods ammo.png
20 mm AP magazines
Mods new main caliber turrets.png
Primary Armament Targeting
Mods ship rangefinder.png
Improved Rangefinder
Mods depth charge.png
Depth Charges
Mods ship art support.png
Artillery Support

As a premium vehicle, all modifications are unlocked for free.

Armament

Primary armament

Turret40 mm 2pdr QF Mk.IIc automatic cannon
Ammunition2240 rounds
Belt capacity56 rounds
Fire rate200 shots/min
Vertical guidance-5° / 70°

The primary armament consists of a single 40 mm 2pdr QF Mk.IIc cannon mounted forwards in front of the bridge. Stock, the mount can traverse horizontally at a rate of 34°/s and vertically at a rate of 21°/s; with the "Primary Armament Targeting" modification installed, this is increased to 40°/s and 25°/s respectively. With a full ammunition load, there are 2,240 rounds of ammunition, or 40 magazines, available for the mount. The gun has a magazine capacity of 56 rounds and a cycle rate of fire of 200 rounds/min. With a stock crew, it can be reloaded in 7.8 seconds; with an aced crew, this is decreased to 6 seconds.

Primary aramament guidance
Horizontal Vertical
±180° -5°/+70°

There are three ammunition types available:

  • Universal: HEF/AP-T/HEF/AP-T
  • 40 mm HE: HEF/HEF/HEF/AP-T
  • 40 mm AP: AP-T/AP-T/AP-T/HEF
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 60 57 50 43 38 34
40 mm HE 60 57 50 43 38 34
40 mm AP 60 57 50 43 38 34

The best ammunition type is 40 mm HE, since it has the highest ratio of HE rounds to AP rounds, making it the most effective against both aircraft and the vast majority of surface targets. Take mostly 40 mm HE along with a several magazines of 40 mm AP for armoured targets.

Secondary armament

Turret2 x 20 mm/70 Oerlikon Mark V autocannon
Ammunition3600 rounds
Belt capacity60 rounds
Fire rate450 shots/min

The secondary armament consists of two 20 mm/70 Oerlikon Mark V cannons in a twin mount aft. Stock, the mount can traverse horizontally at a rate of 51°/s and vertically at a rate of 43°/s; with the "Secondary Armament Targeting" modification installed, this is increased to 60°/s and 50°/s respectively. With a full ammunition load, there are 3,600 rounds of ammunition, or 60 magazines, available for the mount. Each gun has a magazine capacity of 60 rounds and a cycle rate of fire of 450 rounds/min, though the gun on the gunner's left side fires at a slightly faster rate, around 485 rounds/min. With a stock crew, the mount can be reloaded in 10.4 seconds; with an aced crew, this is decreased to 8 seconds.

Secondary armament guidance
Horizontal Vertical
±180° -10°/+60°

There are three ammunition types available:

  • Universal: HEF-T/HEF-I/AP-T
  • 20 mm HE: HEF-T/HEF-I/AP-T/HEF-I
  • 20 mm AP: AP-T/AP-T/AP-T/HEF-I
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 35 33 26 21 18 15
20 mm HE 35 33 26 21 18 15
20 mm AP 35 33 26 21 18 15

The best ammunition type is the 20 mm HE belt, since it has the highest ratio of HE rounds to AP rounds, making it the most effective against both aircraft and the vast majority of surface targets. The Universal belt is a direct downgrade to the 20 mm HE belt in terms of damage, and the 20 mm AP belt isn't really worth taking due to its relatively low armour penetration. To deal with armoured opponents, use the primary 40 mm 2pdr QF Mk.IIc instead. Take only 20 mm HE.

Anti-aircraft armament

2 х Turret2 x 7.72 mm Lewis machine gun, pattern 1916
Ammunition3880 rounds
Belt capacity97 rounds
Fire rate551 shots/min
Main article: Lewis 1916 (7.72 mm)

The anti-aircraft armament consists of four 7.72 mm Lewis 1916 machine guns in two twin mounts, one on either side of the bridge. A total of 7,760 rounds of ammunition, or 80 magazines, are carried for both mounts, 1,940 rounds, or 20 magazines, per gun. Each gun has a magazine capacity of 97 rounds and a cycle rate of fire of 550 rounds/min. With a stock crew, the mount can be reloaded in 18.2 seconds; with an aced crew, this is decreased to 14 seconds. Horizontal and vertical traverse rates are not stated in-game.

Msg-info.png Turrets are named sequentially, clockwise, starting at the bow
Anti-aircraft armament guidance
No.1 Turret (starboard) No.2 Turret (port)
Horizontal Vertical Horizontal Vertical
-45°/+170° -5°/+60° -170°/+45° -5°/+60°

Ammunition types cannot be selected for the anti-aircraft armament on MGB-75. Belt composition and penetration statistics are not stated in-game.

Additional armament

Setup 12 x Mk.VII depth charge
Main article: Mk.VII depth charge

MGB-75 has two possible loadouts:

  1. Without load
  2. 2x Mk.VII depth charge

Depth charges

Mk.VII depth charges numbered according to their drop order (click to expand).

The Mk.VII depth charges are carried amidships, one on either side of the bridge next to the twin 7.72 mm Lewis 1916 machine guns. They are dropped one at a time in the following order:

  1. Starboard
  2. Port

Before spawning, the detonation time delay can be set anywhere between 3 seconds and 10 seconds.

Depth charge characteristics
Mass (kg) Explosive type Explosive mass (kg) TNT equivalent (kg) HE armour penetration (mm) Armoured vehicle destruction radius (m) Fragment dispersion radius (m)
196 TNT 130 130 101 8 122

There is almost no practical reason to use depth charges on any naval vessel in the game. Although they usually result in a one-hit kill if used properly, they are extremely situational, requiring the player to close to point-blank ranges to even use them. In almost every case, anytime a depth charge could be used, the guns can be used instead to greater effect. In fact, depth charges tend to actually be a liability in battle, since they essentially act as exposed ammo racks before they're dropped. They can be shot at, and if destroyed, they have a chance to detonate, instantly destroying the boat.

Despite this, some success can be had in dropping them either next to, or in front of a large, slow target. If dropping them next to the target, remember the depth charge drop order, since it's most likely that only the depth charges dropped on the side closest to the enemy will deal any damage. If dropping in front of the target, rush in from the sides as quickly as possible and drop them all at once directly in front of the target. For both cases, set the depth charge time delay to the minimum 3 seconds, since any higher time delay will only allow the depth charge to sink further away from the target, giving them more time to move out of the way. Again, using depth charges is extremely situational, and they will only be a liability the vast majority of the time, so take them at your own discretion.

Usage in battles

While the MGB-75's primary armament, the 40 mm 2pdr QF Mk.IIc, is a good weapon. It has a very good damage output, and, with a maximum range of roughly 3.1 km, it can outrange any opponent armed with 20 mm cannons. The gun can deal a lot of damage when the rounds hit; however, getting them to land may not always be the easiest task, mainly due to MGB-75's construction. MGB-75 has a relatively short hull, and she isn't particularly heavy for her size, so she is easily thrown around by rough waters. This, of course, makes accurately aiming the gun at long ranges practically impossible unless the sea is calm. In addition to this, MGB-75 has a planing hull, so the bow will lift out of the water when moving at high speeds. The 2pdr QF Mk.IIc can't depress far enough to compensate, so, when on the move, it won't actually be able to target most enemies in an area extending roughly 500 meters in front of the boat. Take care to either turn the hull or to slow down to engage enemies. Other shortcomings of the gun are its relatively long reload and that it's very easy to disable. For the former, if there are less than 20 or so rounds left in the magazine, it's best to fire off the remaining ammunition after each engagement to minimize the chance of needing to reload during the next engagement.

If the 2pdr QF Mk.IIc is knocked out or if it is reloading, switch to the secondary twin 20 mm Oerlikon Mk.V cannons. These guns have a shorter reload than the 40 mm, and they have a much faster traverse and elevation rates, so it tends to be better for close engagements. Since the default position of the mount is to face directly aft, it's best to have it targeting the enemy currently being engaged (default: X + 2) when not in use in order to have it already facing the enemy if it's needed. Of course, this also means that it won't be able to target any other boats or aircraft while the current target is still selected, so try not to be tunnel-visioned and always keep an eye on the surroundings. Aside from that, just like the 2pdr QF Mk.IIc, always be aware of how much ammunition is left in the magazines. If there are less than 40 rounds of so rounds left between the two guns, fire off the remaining ammunition to load a full magazine.

Be careful when engaging any enemy with 3-inch or larger guns. MGB-75 has large ammunition storages, and, if a 3-inch or larger HE round hits anywhere near the ammunition storages, especially the aft pair, it more often than not leads to an ammunition detonation. This is even more so with artillery fire. If the artillery warning displays, leave the area as soon as possible.

The fore 40 mm 2pdr QF Mk.IIc cannon can fire in ~143° to either side, centred forwards. As mentioned before, a blind spot is created when moving at high speeds which prevents the gun from firing in an area that extends ~500 ahead and which covers ~45° to either side. The aft twin 20 mm Oerlikon Mk.V cannons can fire in all directions except for a ~45° arc, centred forwards. When moving at high speeds, this blind arc is increased to ~75°.

Ammunition Choices

For the 40 mm 2pdr QF Mk.IIc cannon, the best ammunition choice is the 40 mm HE because it has the highest ratio of HE rounds to AP rounds, meaning that it will be the most effective against both aircraft and surface targets. The 40 mm HE belt should be the main ammunition choice, but a few of the 40 mm AP belt should also be taken into battle for use against armoured targets.

For the 20 mm Oerlikon Mk.V cannons, the best ammunition choice is the 20 mm HE. There isn't much of a point in using the 20 mm AP belt because the primary armament is much more suited for engaging armoured targets anyway.

Depth Charges

Being anti-submarine weapons and with the present lack of submarines in the game, there is practically no reason to use them. While they can be used against surface targets, this is extremely situational. Sailing up right next to a slower target and dropping a depth charge can lead to some success, though again, this is very situational. If attempting this, remember the order in which the depth charges drop and that there is no reason to use any depth charge activation time setting above the minimum 3 seconds, since higher delay times means the depth charge will sink further, and thus away, from the target. Again, it should be reiterated that this is very situational.

There is no practical reason to take them into battle, especially since, if they're not dropped, they essentially become unarmoured ammo racks.

Pros and cons

Pros:

  • Powerful primary and secondary armament
  • Both primary and secondary armament can rotate 360°
  • Secondary armament: very good elevation and traverse rates; large magazine capacity; good firing arcs

Cons:

  • Blind spot directly in front when moving at high speeds
  • Primary armament: long reload; easily disabled
  • Anti-aircraft armament: long reload; can only elevate 60°; low damage output
  • Unstable firing platform in rough waters
  • Large ammo racks

History

By early 1941, many of the British Power Boat Company (BPB) 60-foot, 63-foot, and 70-foot boats had been completed and were in Royal Navy Coastal Forces service, and already, their weaknesses began to show. The boats were small and lightly constructed, and the living condition for the crew was cramped. Additionally, because of their underpowered engines, they were slow. While their low top speed was certainly acceptable for the anti-submarine work, as they were initially built to perform, it was insufficient by 1941 as most of the boats had been converted into motor gun boats by this point. Thus, in 1941, BPB began designing a larger, faster boat.

BPB's new design had a length of 71 feet 9 inches (21.9 m), a beam of 20 feet 7 inches (6.3 m), and a draught of about 4 feet 3 inches (1.3 m). It was powered by three Packard petrol engines driving three shafts which allowed it to achieve a top speed of 42 knots. The BPB 71'9" boats formed the bulk of Coastal Forces' MGB fleet until the introduction of the larger and more heavily-armed Fairmile D boats. In total, 96 boats were built:

  • MGBs 74-81: ordered in November 1940 as MA/SBs, all completed in 1942 as MGBs. Any surviving boats by September 1943 were refitted with a pair of 18-inch torpedo tubes and redesignated as MTBs 412-416. Any of the boats that survived the war were disposed of in October 1945.
  • MGBs 107-119: ordered in November 1940 as MA/SBs, canceled in March 1941, and reordered in February 1942, all completed in 1942 as MGBs. Any surviving boats by September 1943 were refitted with a pair of 18-inch torpedo tubes and redesignated as MTBs 417-418 and 430-438. Any of the boats that survived the war were disposed of either in March 1945 or in October 1945. Their fates are as follows:
  • MGBs 120-130: ordered in May 1942 as MGBs, all completed in 1943. All boats were refitted in September 1943 with a pair of 18-inch torpedo tubes and redesignated as MTBs 439-449. Most of the boats that survived the war were disposed of in October 1945.
  • MTBs 450-489: ordered as MGBs, all completed between 1943-1945 as MTBs. Any of the boats that survived the war were disposed of at various dates or used as controlled targets.
  • MTBs 490-500: ordered as MTBs, all completed between 1944-1945. Any of the boats that survived the war were disposed of at various dates or used as controlled targets, with the exception of MTB-496 and MTB-498. These were refurbished in 1949 and renumbered MTB-1596 and MTB-1598 to form the "Proud" class along with MTBs 1505-1509, MTB-1519, and MTB-1522. They were given the names "Proud Patriot" and "Proud Patroller", respectively. The "Proud" class boats were all sold in June 1958.
  • MTBs 501-509: ordered as MTBs, all completed in 1945. All of the bats survived the war. MTBs 501-504 were sold or disposed of at various dates. MTBs 505-509 were refurbished in 1949 and renumbered MTBs 1505-1509 to form the "Proud" class along with MTB-1596, MTB-1598, MTB-1519, and MTB-1522. They were given the names "Proud Fusilier", "Proud Grenadier", "Proud Guardsman", "Proud Highlander", and "Proud Knight", respectively. The "Proud" class boats were all sold in June 1958.
  • MTBs 519-522: ordered as MGBs, all completed in 1946 as MTBs. With the exception of MTB-520, they were refurbished in 1949 and renumbered MTB-1519, MTB-1521, and MTB-1522. MTB-1519 and MTB-1522 formed the "Proud" class along with MTBs 1505-1509, MTB-1596, and MTB-1598. They were given the names "Proud Lancer" and "Proud Legionary", respectively. The "Proud" class boats were all sold in June 1958.

MGB-75 was part of the original order placed in November 1940. She was ordered as a motor anti-submarine boat but was completed on 8th May 1942 as a motor gun boat. MGB-75 was commanded by the following:

  • T/Lt. L.G.R. Campbell, RNVR: October 1942 to February 1943
  • T/S.Lt. F.J. Head, RNVR: April 1943 to June 1943
  • T/S.Lt. W.G.L. Salmon, RNVR: From June 1944 onwards

MGB-75 served as part of the 6th MGB Flotilla with HMS Beehive at Felixstowe through 1943. In September 1943, MGB-75 received her refit and was redesignated as MTB-413. Through 1944, MTB-413 served as part of the 1st MTB Flotilla at Portsmouth. MTB-413 survived the war and was disposed of in October 1945.

Media

GEN LIVE WT 1 HPL.jpg

See also

External links

Bibliography

  • Konstam, Angus (2010). British Motor Gun Boat 1939–45. Osprey Publishing Ltd. ISBN 978-1-84908-077-4.


Britain boats
Motor torpedo boats  Brave Borderer · Dark Aggressor · Dark Aggressor TD · Fairmile D (617) · Fairmile D (697) · Fairmile D (5001) · HMS Gay Archer
  MTB-1(1) · MTB-1(2) · MTB Vosper · MTB Vosper(2) · MTB-422
Motor gun boats  Dark Adventurer · Fairmile A (ML100) · Fairmile B (ML345) · Fairmile C (312) · Fairmile C (332) · Fairmile D (601) · Fairmile H LCS(L)(2)
  HMAS Arrow · HMAS Fremantle · MGB-61 · MGB-75 · ML 1383 · SGB Grey Fox · SGB Grey Goose
Gunboats  HMS Spey

Britain premium ships
Motor torpedo boats  MTB-1(2) · MTB-422 · Fairmile D (5001) · HMS Gay Archer
Motor gun boats  MGB-75 · SGB Grey Goose
Gunboats  HMS Spey
Sub-chasers  LÉ Orla
Frigates  HMS Whitby
Destroyers  HMS Montgomery · HMS Valhalla · HMS Verdun · ORP Garland · HMS Jervis · HMCS Haida · HMS Mohawk · HMS Cadiz · HMS Diamond
Light cruisers  HMS Belfast
Battleships  HMS Iron Duke