Why are there no WIG Type Unmanned Surface Vehicles

[Gannet]

While reading the following article, it baffles me why there are no modern examples of wing in ground (WIG) effect unmanned surface vessels

Unmanned Surface Vehicles: Past, Present, and Future
By Helmut H. Portmann, Seth L. Cooper, Mathew R. Norton, and David A. Newborn
http://www.globalatlantic.com/unmanned.html

They must be secret because the benefits are way too obvious:
1. Longer range (more standoff distance especially when compare to the AN/WLD-1 (REMOTE MINEHUNTING SYSTEM) with its semi-submersible surface vessel). This also means you are less likely showing your intend to the enemy.
2. Higher speed capability than planing, hydrofoil, and definitely semi-submersible surface vessels.
3. Mines are less of a threat.
4. Reduced detection by hydrophones
5. No visible wake or contrails from above
6. Higher transport efficiency Payload Weight/Power Required
7. The cost is definitely less than the cost of the AN/WLD-1 Semi-Submersible.

Also, I envision an unmanned wig-type surface vessel carrying, powering, and controlling the underwater submersible minehunting portion of the system or a Intelligence, Surveillance Reconnaissance Unmanned Underwater Vessel and provide a communication link with the remote base station.

Does anyone have any additional thoughts or insights on this subject.

 

[Firefly 2]

As I see it there have been two types of WIG vessels tested to this day:
- the true WIG ( like the Russian Ekranoplan)
- the SES, which acts like a contained WIG effect ( that is if my understanding of the principle is correct)

Now, there are a certain amount of safety concerns.
A heavy mass moving at several 100 knots at wavetop height doesn't inspire that much confidence, and the ekranoplan have suffered a few losses due to exactly this.
Three way outlay of the Orlan(?) ekranoplan, a heavy transport for long range amphibious operations.

taken from http://autospeed.com/cms/article.html?&A=1306&P=1 , very interresting

Armed Ekranoplan, fitted with launching tubes for the SS-N-22 Sunburn anti-ship missile.

I truly love the concept.
It seems though that, as so often, the idea seems too dodgy tor really get both the financial and political backing to really gain momentum against more conventional options.

Secondly the SES:

As far as I, there is only one class of ships in operational use that can be classified as being SES: the Norwegian Skjold class of patroll boats ( although the Norwegian navy now classifies these ships as corvettes, probably to counter Russian activism in the region according to DSI magazine)

Notwithstanding their small size, these are heavily armed and will be fitted with the NSM missile when ( or if, since the first tests where disappointing) it enters service.

Interresting as this ship may be, it's a far cry from he 3000 ton LSES envisioned by Lockheed, Bell, Aerojet or Litton in 1972. This truly could have been a viable warship. I have an artists rendition of it in this 1978 book called " The US War Machine" ( Salamander Books). Can't find it online though.

Why haven't the concepts gained more interrest? They still do, the Boeing Pelican is a modern version of the Ekranoplan in many ways, designed to be a long range heavy lifter much like the Orlan(?) mentioned above. Modern technology might solve a lot of the inherent troubles of these designs.
As for the SES... Did it not match the strategic views of the day? Was it ahead of its time? Was it not cost effective? I have trouble finding US sources regarding these bigger projects. Any input would be appreciated.

 

[ouroboros]

Unmanned WIG's for fast insertion of AUV's would be an interesting force multiplier, either as a generic delivery vehicle, as well as a release/retrieve mothership with possible different launch/pickup points. The seaskimming aspects make it attractive to avoid being caught on radar, plus good efficiency and high cargo capacity are attractive. The only problem is matters of scale. WIG's work better when they are really big, and size dictates their reasonable seaskimming heights. Too small, and a random wave that is larger than those around it by not that large of a margin runs the risk of severely damaging the WIG, int he worst case causing it to dive underwater itself as it smacks into the back of a wave. Coupled with the low height of the vehicle itself, it would be hard to detect such dangerous waves in advance due to limited sight horizon, as well as generic floating obstacles in the water such as the poles for crabpot buoys. Though one could argue an unmanned WIG could do more violent maneuvering to avoid obstructions and follow the nape of the sea.

A simple concept would be a catamaran fuselage with a forward canard/bridge wing and a rear forward swept crescent wing. Your AUV would be grappled between the hulls by attachments from the wings, for easy release and catch. Engine placement on the canard wing then is a question of whether you want to do a PAR-WIG or not.

 

[Rickshaw]

How well do WIG cope with rough weather and water?

 

[Gannet]

A simple concept would be a catamaran fuselage with a forward canard/bridge wing and a rear forward swept crescent wing. Your AUV would be grappled between the hulls by attachments from the wings, for easy release and catch. Engine placement on the canard wing then is a question of whether you want to do a PAR-WIG or not.

PAR-WIG craft (Power Augmented Ram Wing in Surface effect) is what I envision. Similar to the attached; however, with twin engines and the UUV or AUV would be enclosed within the fuselage in its storage/launching/recovery cradle. This storage cradle should have the capability of downloading stored data, re-missioning programming, and recharging energy source.

Its capability should be the same as Sea Based seaplanes which based on open ocean wave data, the desired goal is to have full operational capability in sea state 4 (below 8 feet in significant wave height), with limited operation in sea state 5 (below 13 feet in significant wave height). Which I believe is attainable.

 

[RP1]

There is some confusion here.

1. SES.

SES, Surface Effect Ship, is quite different from WIG. SES are essentially a hovercraft with rigid side-walls and flexible seals at the bow and stern. A Shipbucket of the 3K SES is here:

http://s90.photobucket.com/albums/k279/shipbucket/Never%20build%20designs/?action=view&current=USAFF3000tSES19901.gif

In common with hovercraft this is aerostatic lift, provided by the high pressure inside the cushion. Of course, the cushion pressure needs to be maintained somehow and that is what the lift fans are for. They do not lift the craft directly, and lift is not generated through forward speed.

2. The problem is that WIG are also referred to as WISE. These are aerodynamic craft which use various phenomena to generate lift when moving, but essentially based around the "ground effect" that increases the lift of a wing close to the ground. Some WIG can direct jet efflux under the wing to generate lift, but this is primarily for take-off, and is not really the same as an SES. In WIG, the lift is generated through the motion of the craft.

RP1

 

[RP1]

Uses of WIG for UxVs

There are several issues to consider regarding the use of WIG craft as UxVs. Seakeeping is more significant for a small UxV than for a larger craft, and this will limit their useability. Of course, the current generation of USVs are based on small speedboats and will not perform very will in a rough sea anyway.

Another issue is just what the U-WIG would be for. Compared to a displacement surface craft, it will have higher signatures in some areas, not have as much persistence (higher fuel usage and shallow draft when hullborne leading to worse seakeeping) and a lower payload weight fraction for a given weight of craft, but the potential advantages of much greater speed and (ironically), shallower draft. The concept of using a U-WIG to dash in to a danger area is probably a good one - there are some surface hull designs that could provide this capability for small USVs without sacrificing seakeeping, such as the HYSWAS.

From a cynical perspective, one might point out that the introduction of such fast UxVs would remove the requirement for LCS - better to carry lots of fast, sea-worthy and probably larger UxVs on a slower, larger surface ship.

In general, one should consider, that we are probably at the Wright Flyer stage of UxV development, or maybe some early Great War machine. Similarly, UxV carriers such as LCS are probably similar to HMS Engadine - yes, she was an aircraft carrier, yes, the aircraft she carried flew, but neither is a good representation of a modern carrier and it's air wing. In other words, the future may be a completely different shape to the now.

RP1

 

[ouroboros]

Not the best since it's pure fiction and wouldn't even fly right, but this is the only example pic I had on hand of the idea...

 

[SteveO]

Here's a Lockheed patent of a Anti-submarine warfare UAV http://www.google.com/patents?id=e90JAAAAEBAJ&printsec=abstract&zoom=4&dq=Lockheed+UAV#PPA1,M1

 

[Firefly 2]

There is some confusion here.

1. SES.

SES, Surface Effect Ship, is quite different from WIG. SES are essentially a hovercraft with rigid side-walls and flexible seals at the bow and stern. A Shipbucket of the 3K SES is here:

http://s90.photobucket.com/albums/k279/shipbucket/Never%20build%20designs/?action=view&current=USAFF3000tSES19901.gif

In common with hovercraft this is aerostatic lift, provided by the high pressure inside the cushion. Of course, the cushion pressure needs to be maintained somehow and that is what the lift fans are for. They do not lift the craft directly, and lift is not generated through forward speed.

2. The problem is that WIG are also referred to as WISE. These are aerodynamic craft which use various phenomena to generate lift when moving, but essentially based around the "ground effect" that increases the lift of a wing close to the ground. Some WIG can direct jet efflux under the wing to generate lift, but this is primarily for take-off, and is not really the same as an SES. In WIG, the lift is generated through the motion of the craft.

RP1

Sorry for the confusion, it was how it was explained to me.
Thanks for the clarification.

Here's a Lockheed patent of a Anti-submarine warfare UAV http://www.google.com/patents?id=e90JAAAAEBAJ&printsec=abstract&zoom=4&dq=Lockheed+UAV#PPA1,M1

That looks cool, but as so often in such patents there seems to be little space for such a thing as fuel... IMO at least.

 

[Gannet]

Found THE NAVY UNMANNED SURFACE VEHICLE (USV) MASTER PLAN, 23 July 2007. In this document on page 6 & 7 they defined a USV as follows:
To clearly focus the USV Master Plan on its chartered tasks, the following definitions were adopted for the purpose of this plan:
• Scope of Plan - Tactical systems capable of air or sea transport (reference (j))
• Unmanned - Capable of unmanned operation. Can be manned for dual use or Test and Evaluation (T&E). Has varying degrees of autonomy.
• Surface Vehicle - Displaces water at rest. Operates with near continuous contact with the surface of the water.
Interface of the vehicle with the surface is a major design driver.
Although this definition includes hydrofoils and semi-submersible (i.e., continuously snorkeling) crafts, it specifically excludes UUVs operating at or near the surface, hovercraft, surface effect aircraft and target drones that are used exclusively for training or evaluation and are part of a separate legacy program (e.g., undersea and surface targets operated on an instrumented range as targets). ???

Are they saying that unmanned hovercrafts & surface effect aircraft are only good for targets? Something stinks here. :'(

I think the military should stick to defining missions and their required capabilities and let science and technology determine the HOW