Regimental Infantry Carrier (WiGE) "Sea Monster"

[Seer]

I've been looking in to how combat vehicle transports are built and this is the result of wondering if it were possible to transport an entire Regiment of conventional infantry at once on a SV hovercraft. The answer to that was obviously not, but you can with a WiGE. I'm aware of the Koi/Nishikigoi but they didn't quite scratch the itch of wanting a landing craft in the spirit of the Lun-class ekranoplan. Here, the Sea Monster is a landing craft dedicated to carrying light and/or heavy infantry for a combined arms assault on a coastline.

The TRO below has been edited for presentation and because MML's text export had formatting issues. It also didn't include important info, like crew numbers, the engine rating, and troop capacity. This is a Dark Age-era craft.

Code: [Select]

Regimental Infantry Carrier (WiGE) "Sea Monster"

Mass: 240 tons
Movement Type: Wing in Ground Effect
Power Plant: Fusion
Cruising Speed: 54 kph
Maximum Speed: 86.4 kph
Armor: Ballistic-Reinforced
Armament:
     1 Arrow IV
     2 LB 2-X AC
     2 Anti-Missile System
Introduction Year: 3150
Tech Rating/Availability: E/X-X-X-E
Cost: 27,450,555 C-bills

Type: Regimental Infantry Carrier
Chassis Type: Wing in Ground Effect (Large)
Technology Base: Inner Sphere (Experimental)
Mass: 240 tons
Battle Value: 1,532

Equipment                                         Mass (tons)
Chassis/Controls                                  94.5
Engine/Trans.                 850 Fusion          31.5
Cruise MP: 5
Flank MP: 8
Heat Sinks                    0                      0
Fuel                                                 0
Turret                                             1.5
Armor Factor (B-R)            124                 10.5

                          Internal   Armor   
                          Structure  Value   
     Front                   24        18   
     Front R/L Side        24/24     18/18   
     Rear R/L Side         24/24     18/18   
     Rear                    24        16   
     Turret                  24        18   

Weapons
and Ammo                        Location    Tonnage   
2 Anti-Missile System           Sponson       1.0     
2 LB 2-X AC                     Sponson       12.0   
Arrow IV                         Turret       15.0   
LB 2-X AC Ammo (45)               Body        1.0     
Anti-Missile System Ammo (24)     Body        2.0     
LB 2-X Cluster Ammo (45)          Body        1.0     
Arrow IV Ammo (10)                Body        2.0     
Arrow IV Fuel-Air Ammo (5)        Body        1.0     

Crew
    Base:      3
    Gunners:   6
    Other:     0
    Officers:  2
    Total:     11

Cargo
    None

Carrying Capacity
    Troops (65.0 tons)       2 Door 

Equipment Notes:
Features Amphibious, Armored Chassis Chassis and Controls Modifications (56.5 tons; incorporated in Chassis/Controls)
CASE (0.5 tons)
Advanced Fire Control (3 tons)
Vehicular Sponson Turret (2; 0.75 tons each)

Equipment                          Loc 
Vehicular Sponson Turret          FRRS 
Vehicular Sponson Turret          FRLS 
SV Chassis Mod [Amphibious]        BD   
SV Chassis Mod [Armored Chassis]   BD   
CASE                               BD   
Advanced Fire Control              BD   Design notes:

• It can carry 3 full Battalions, or 1 Regiment, of 756 conventional infantry, plus some room for extra support staff. Its total capacity is 765 (rounded up).
• It can also carry up to 65 Battle Armor troopers, or a Company's worth.
• Its sponson turrets provide a 180° arc of coverage for its armament on both sides. The LB 2-X's are mainly for AA duties, used to dissuade any attempted bombing runs or aero attacks while the Sea Monster is on the move. They can also provide light covering fire for disembarking infantry if no aero targets present themselves. The AMS' are mounted with them to fend off missile attacks in the same arc.
• The Arrow IV launcher is mounted in a turret, giving it a full 360° arc of fire, and should be used to bombard the landing zone ahead of arrival, creating cover for the infantry as well as softening up any enemy emplacements. 3 tons of reloads provide some flexibility in munitions and ammo for limited artillery support upon landing.
• It is outfitted with Ballistic-Reinforced armor to provide the maximum possible defense against explosives and powerful ballistic weapons.
• I would give it Environmental Sealing to provide crew and passengers NBC protection but it would cost 91 tons.

Edit 1: I made a companion for the "Sea Monster" above called the "Sea Dragon". It's also a landing craft but with a different mission.

Code: [Select]

Heavy Vehicle Carrier (WiGE) "Sea Dragon"

Mass: 240 tons
Movement Type: Wing in Ground Effect
Power Plant: Fusion
Cruising Speed: 54 kph
Maximum Speed: 86.4 kph
Armor: Ballistic-Reinforced
Armament:
     4 Rocket Launcher 10
     2 Anti-Missile System
Introduction Year: 3150
Tech Rating/Availability: E/X-X-X-E
Cost: 19,036,275 C-bills

Type: Heavy Vehicle Carrier
Chassis Type: Wing in Ground Effect (Large)
Technology Base: Inner Sphere (Experimental)
Mass: 240 tons
Battle Value: 1,015

Equipment                                         Mass (tons)
Chassis/Controls                                  92.0
Engine/Trans.                 850 Fusion          31.5
Cruise MP: 5
Flank MP: 8
Heat Sinks                    0                      0
Fuel                                                 0
Turret                                             1.5
Armor Factor (B-R)            124                 10.5

                          Internal   Armor   
                          Structure  Value   
     Front                   24        20   
     Front R/L Side        24/24     21/21   
     Rear R/L Side         24/24     21/21   
     Rear                    24        20   

Weapons
and Ammo                        Location    Tonnage   
2 Anti-Missile System           Sponson       1.0     
4 Rocket Launcher 10            Sponson       2.0   
Anti-Missile System Ammo (24)     Body        2.0     

Crew
    Base:      3
    Gunners:   1
    Other:     8
    Officers:  1
    Total:     13

Cargo
    Bay 1:  Heavy Vehicle (1)       2 Door   

Carrying Capacity
    None

Equipment Notes:
Features Amphibious, Armored Chassis Chassis and Controls Modifications (56.5 tons; incorporated in Chassis/Controls)
CASE (0.5 tons)
Advanced Fire Control (0.5 tons)
Vehicular Sponson Turret (2; 0.25 tons each)

Equipment                          Loc 
Vehicular Sponson Turret          FRRS 
Vehicular Sponson Turret          FRLS 
SV Chassis Mod [Amphibious]        BD   
SV Chassis Mod [Armored Chassis]   BD   
CASE                               BD   
Advanced Fire Control              BD   Design notes:

• It can carry any combination of combat-ready vehicles up to 100 tons (e.g. two Schildkröte Line Tanks).
• Its sponson turrets mount rockets for light covering fire as the vehicles disembark, and the AMS' are mounted with them. It has no other weapon systems due to its heavy cargo.
• An alternate configuration could strip out the rockets (and thus the advanced fire control) and a half ton of armor to mount a Blue Shield Particle Field Damper to protect against heavy-hitting PPCs, but this would increase the price to 28,674,325 C-Bills. Its BV would decrease slightly to 1002.
• It, too, is outfitted with Ballistic-Reinforced armor but the armor is slightly heavier in practice because it doesn't have a turret.
• See above for the environmental sealing issue.
• It's not as flashy but offers the most flexibility for the tonnage. The design could swap out the 100 ton heavy vehicle bay for, e.g., a 90 ton foot infantry bay with a temperature controlled environment, facilities for longer flights, and 10 tons of cargo. It would be able to carry 504 troops (two Battalions). A 50 ton Light Vehicle bay could also be installed with a 45 ton infantry bay for 252 troops (one Battalion), and another 5 for cargo. Finally, a 96 ton Battle Armor bay would carry 48 troopers (3 Platoons) and 4 tons of cargo.

Never made anything quite like these before, so hopefully they're okay. I've attached the .blk's for reference. Imagine six of these thundering towards an unsuspecting coastline. That's what I was going for.

Edit 2: This last one is based on the Papercraft WiGE, which is a great concept with some obvious flaws: as it lacks the amphibious chassis modification it can't unload while afloat*, and, as noted, its armor is a real hindrance to putting it in harm's way. You can take care of the latter by upping its structural and engine tech rating to E and the saved weight allows you to armor the chassis. Unfortunately, you can't do that and make it amphibious; it's too heavy. You can't make it amphibious instead of armoring the chassis at tech E either, as it's overweight even without an armament. Assuming a hyper-advanced tech level of F/F it's still impossible to have an armored and amphibious 'mech landing craft at 5/8 movement, sadly. In that sense, this is not a craft for creating a beachhead, and should be considered separate to the above. So how do you make the Papercraft WiGE more viable?

*All the Koi variants have this modification which suggests it's essential for letting a WiGE unload on the beach. See TRO: Vehicle Annex Revised: "Using the same combination of flotation tanks and powerful pumps as the Koi, the Ryu can open its bay doors while afloat without fear of being swamped." (p. 90) All WiGE float but they're in danger of being flooded without this modification. If otherwise, a lot of the problems go away due to the weight savings. There's a related thread on the Total Warfare rules subforum about whether WiGE's need the amphibious chassis to land on water or not; it's still unresolved. Until there's an official ruling on that contradiction, it must be assumed that the modification is necessary.

The above leaves no option but to use hyper-advanced technology. Only then is it possible to build a WiGE craft that can deploy a 'mech from an armored and amphibious chassis. How exactly it would get on and off is a problem for the engineers, not for us.

Here's the (truly) experimental "Sea Eagle".

Code: [Select]

BattleMech Carrier (WiGE) "Sea Eagle"

Mass: 240 tons
Movement Type: Wing in Ground Effect
Power Plant: Fusion
Cruising Speed: 32.4 kph
Maximum Speed: 54 kph
Armor: Ballistic-Reinforced
Armament:
     None
Introduction Year: 3150
Tech Rating/Availability: F/X-X-X-E
Cost: 11,712,006 C-bills

Type: BattleMech Carrier
Chassis Type: Wing in Ground Effect (Large)
Technology Base: Inner Sphere (Experimental)
Mass: 240 tons
Battle Value: 501

Equipment                                         Mass (tons)
Chassis/Controls                                  71.0
Engine/Trans.                 370 Fusion          14.5
Cruise MP: 3
Flank MP: 5
Heat Sinks                    0                    0.0
Fuel                                               0.0
Armor Factor (B-R)             54                  4.5

                          Internal   Armor   
                          Structure  Value   
     Front                   6         9   
     Front R/L Side         6/6       9/9   
     Rear R/L Side          6/6       9/9   
     Rear                    6         9   

Weapons
and Ammo                        Location    Tonnage   
None                                -          -

Crew
    Base:      3
    Gunners:   0
    Other:     0
    Officers:  0
    Total:     3

Cargo
    Bay 1:  Mech (1)       2 Door   

Carrying Capacity
    None

Equipment Notes:
Features Amphibious, Armored Chassis Chassis and Controls Modifications (44 tons; incorporated in Chassis/Controls)

Equipment                          Loc 
SV Chassis Mod [Amphibious]        BD   
SV Chassis Mod [Armored Chassis]   BD   Design notes:

• What makes the "Sea Eagle" possible is the structural rating of F — everything else is tech E — and the MP being lower, requiring less mass for the engine. Since it has less MP, it would slow the above craft down during transit. Additionally, any loss of MP would ground it. If the engine tech rating was increased to F as well, it would be possible to maintain 4/6 movement and thus have some margin for MP loss. Alternatively, that extra mass could be put towards more armor or some weapons.
• Its key weakness is that it must maintain flanking speed in order to stay airborne, which puts it at risk of sideslipping during a turn. On a vast ocean this is more unnerving than truly dangerous, but puts it at risk of accidentally colliding with another craft during a landing.
• It may have some armor but it is completely unarmed, so it's best not deployed independently of supporting craft. Rather than landing on a defended shoreline, it should unload while afloat, letting the 'mech walk a short distance underwater or, ideally, use UMUs to cross the final stretch. That way it can make a quicker and safer exit. Provided the enemy doesn't have sonar coverage, this would be a good method for covert insertions too.
• In other words, it will arrive late to any landing unless operating alone, and it won't be able to deliver the 'mech to a hot LZ without putting itself, and likely others, at significant risk. Despite this, it can deliver up to 100 tons of BattleMech across the water or, if needed, into the water.

[maxcarrion]

I feel this is almost the definition of "they spent so long wondering if they could, they forgot to consider if they should".

A super heavy Wige specifically for carrying almost 800 troops is a huge case of eggs in one basket.  I see no real benefit over say 3 much smaller Wige carrying a battalion each, if you're putting them anywhere an enemy with guns even that is pretty extreme.

[Seer]

Even in the real world an amphibious vessel carrying up to 500 troops isn't unknown (see the Zubr-class). Keep in mind that the armor on these things is as heavy as it gets for a support WiGE; three smaller WiGE are comparatively more vulnerable to being destroyed, even if you would lose fewer troops in such an incident. It's pretty cheap for what it does too, and landing it is much simpler (and safer) than with an aero unit. So it's not without advantages. Rather than making it smaller, it would be wiser to cut back on its troop capacity to mount more weapons, give it an ECM, that sort of thing. I might get around to that.

[Dragon Cat]

I like it I wouldn't use it for a front line job but second line support sure thing, arty keeps it useful too

[Simon Landmine]

Glad that someone managed to make something more useful than my Papercraft! I suppose not trying to fit 150 tons of bay into all of them helped. Nice work making the Sea Eagle amphibious, too!

For tactical purposes, the Sea Eagle is probably similar to the Papercraft - moving 'mechs long distances across deserts or oceans, when you don't have a DropShip available for the purposes. Although in emergencies, they could also be used to carry out amphibious landings onto secured LZs. (I've got more than a couple of maps that would work for that.)

Hopefully they get the 'debussing vehicles from Large Support Vehicles' glitch sorted in MM soon, so that I can try those out.

[maxcarrion]

Even in the real world an amphibious vessel carrying up to 500 troops isn't unknown (see the Zubr-class). Keep in mind that the armor on these things is as heavy as it gets for a support WiGE; three smaller WiGE are comparatively more vulnerable to being destroyed, even if you would lose fewer troops in such an incident. It's pretty cheap for what it does too, and landing it is much simpler (and safer) than with an aero unit. So it's not without advantages. Rather than making it smaller, it would be wiser to cut back on its troop capacity to mount more weapons, give it an ECM, that sort of thing. I might get around to that.

Sure, but what is the use case where you are better off with these huge sea monsters in your fleet where you aren't better off with a mix of logistics and combat vehicles.

 The Zubr makes sense in the real.world because you need something that can lift an MBT onto a beach and, since you have one, you might stick troops in it.

At 240T and lifting only 65T the sea monster has a lot of things it can't do in order to make it somewhat combat survivable. 

If instead you used a 100T logistics WIGE like the Nessie which lifts 54T

https://bg.battletech.com/forums/non-combat-vehicles/nessie-support-wige/msg1187731/#msg1187731

Plus a 50T arrow WIGE and 2x45T IFV WIGE

You could, for the same weight, lift the same weight, better secure landing zones, run less risk with high value assets and, most importantly, fit everything in combat vehicle bays which allows them to dock inside large naval support vessels and dropships and make orbital insertion drops. 

[Seer]

@Dragon Cat & Simon Landmine: Thanks for the kind words. I went back over the Sea Monster to see what defensive changes I could make. None of them come cheap.

The main obstacle to significant armament changes is critical space. Plenty of tonnage but nowhere to put it. The best weapons for the critical space are energy weapons, as with lots of tonnage to spare adding more heat sinks isn't an issue. The best defensive options are an Armored Motive System, Angel ECM, and a Supercharger... for an enormous increase in unit price. An Armored Motive System costs 36 tons and 38,160,000 C-Bills, which I found exorbitant, but the other two are justifiable. So here's the result.

Code: [Select]

Battalion Infantry Carrier (WiGE) "Sea Monster"

Mass: 240 tons
Movement Type: Wing in Ground Effect
Power Plant: Fusion
Cruising Speed: 54 kph
Maximum Speed: 108 kph
Armor: Ballistic-Reinforced
Armament:
     1 Arrow IV
     2 ER PPC
     2 Anti-Missile System
     1 Small Pulse Laser
Introduction Year: 3150
Tech Rating/Availability: F/X-X-X-E
Cost: 43,470,335 C-bills

Type: Battalion Infantry Carrier
Chassis Type: Wing in Ground Effect (Large)
Technology Base: Inner Sphere (Experimental)
Mass: 240 tons
Battle Value: 2,658

Equipment                                         Mass (tons)
Chassis/Controls                                  94.5
Engine/Trans.                 850 Fusion          31.5
Cruise MP: 5
Flank MP: 8
Heat Sinks                    32                  32.0
Fuel                                               0.0
Turret                                             1.5
Armor Factor (B-R)            124                 10.5

                          Internal   Armor   
                          Structure  Value   
     Front                   24        18   
     Front R/L Side        24/24     18/18   
     Rear R/L Side         24/24     18/18   
     Rear                    24        16   
     Turret                  24        18   

Weapons
and Ammo                        Location    Tonnage   
2 Anti-Missile System           Sponson       1.0     
2 ER PPC                        Sponson       14.0 
Small Pulse Laser                Front        1.0     
Arrow IV                         Turret       15.0   
Anti-Missile System Ammo (24)     Body        2.0     
Arrow IV Ammo (10)                Body        2.0     
Arrow IV Fuel-Air Ammo (5)        Body        1.0     

Crew
    Base:      3
    Gunners:   6
    Other:     0
    Officers:  2
    Total:     11

Cargo
    None

Carrying Capacity
    Troops (22.5 tons)       2 Door 

Equipment Notes:
Features Amphibious, Armored Chassis Chassis and Controls Modifications (56.5 tons; incorporated in Chassis/Controls)
Supercharger (3.5 tons)
Angel ECM Suite (2 tons)
CASE (0.5 tons)
Advanced Fire Control (3 tons)
Targeting Computer (4 tons)
Vehicular Sponson Turret (2; 0.75 tons each)

Equipment                          Loc 
Vehicular Sponson Turret          FRRS 
Vehicular Sponson Turret          FRLS 
SV Chassis Mod [Amphibious]        BD   
SV Chassis Mod [Armored Chassis]   BD   
CASE                               BD   
Advanced Fire Control              BD   
Angel ECM Suite                    BD   
Supercharger                       BD   Design notes:

• The Supercharger isn't exactly cheap at 3,339,000 C-Bills, or risk free, but appreciably increases the max speed; useful in an emergency. The Angel ECM puts its overall tech level at F but these are commonly available in the Dark Age.
• A 22.5 ton Infantry Compartment can hold nine 2.5 ton Platoons (in MegaMek) or, on the tabletop, 265 troops (rounded up). A Battalion either way. I decided to make it MM-friendly since I doubt this will see much use IRL.
• The LB 2-X's are gone in exchange for two ER PPCs and a Small Pulse Laser augmented by a Tarcomp. The SPL covers the front for some extra close-range firepower and will help prevent boarding actions. For maximum firepower, the SPL can be swapped out for an X-Pulse version and the troop compartment reduced to 21.5 tons, but this isn't MM-friendly.
• It's 16,019,780 C-Bills more over the original. Its BV is 1,126 more as well. You get what you pay for.

At 240T and lifting only 65T the sea monster has a lot of things it can't do in order to make it somewhat combat survivable.

Yes, but it is combat survivable. As I said, making things smaller comes with sacrifices. The Nessie isn't amphibious, doesn't have an armored chassis, and is unarmed. It's a lot cheaper and a lot more vulnerable, as you would expect for a pure support craft. Sacrificing an armament, it is possible to make a smaller WiGE with the same 65 ton lifting capability that's also armored and amphibious for less than 6 million C-Bills. This is as cheap and cheerful as it gets for something combat survivable with that specific capability.

Code: [Select]

Regimental Infantry Carrier (WiGE) "Sea Beast"

Mass: 145 tons
Movement Type: Wing in Ground Effect
Power Plant: Fusion
Cruising Speed: 54 kph
Maximum Speed: 86.4 kph
Armor: Ballistic-Reinforced
Armament:
     None
Introduction Year: 3150
Tech Rating/Availability: E/X-X-X-E
Cost: 5,865,000 C-bills

Type: Regimental Infantry Carrier
Chassis Type: Wing in Ground Effect (Large)
Technology Base: Inner Sphere (Standard)
Mass: 145 tons
Battle Value: 483

Equipment                                         Mass (tons)
Chassis/Controls                                  55.5
Engine/Trans.                 480 Fusion          19.0
Cruise MP: 5
Flank MP: 8
Heat Sinks                    0                    0.0
Fuel                                               0.0
Armor Factor (B-R)            66                   5.5

                          Internal   Armor   
                          Structure  Value   
     Front                   16        12   
     Front R/L Side        16/16     11/11   
     Rear R/L Side         16/16     11/11   
     Rear                    16        10   

Weapons
and Ammo                        Location    Tonnage   
None                                -          -

Crew
    Base:      3
    Gunners:   0
    Other:     0
    Officers:  0
    Total:     3

Cargo
    None

Carrying Capacity
    Troops (65.0 tons)       2 Door 

Equipment Notes:
Features Amphibious, Armored Chassis Chassis and Controls Modifications (34.5 tons; incorporated in Chassis/Controls)

Equipment                          Loc 
SV Chassis Mod [Amphibious]        BD   
SV Chassis Mod [Armored Chassis]   BD   You could also make smaller WiGE craft capable of carrying around a Battalion each, armored and amphibious, for cheaper but at that point it's getting debatable whether to give it BAR 10 armor since it can carry so little of it. So more and more it becomes something else entirely.

[Dragon Cat]

I'd see the Nessie as a civilian transporter

[maxcarrion]

The Nessie could easily be a civilian transport, I'd not put one in the line of fire, I'd not put a sea monster with 700 troops in it anywhere it could.be shot at either.  But if you were making a landing at a semi-secure beach I'd rather send a Lance of combat vehicles with a forward group to secure and then land a Nessie than I would bring in a sea monster to a potentially hot LZ loaded with a full regiment.