Towed Active Shipboard Electronic Decoy

You said:

I wrote a report in 1987 which featured a towed sled supporting an active electronic countermeasures system. The concept was rapid development as the sled was a hydrofoil from the MH-53 airborne mine countermeasures program and the electronics system was used in the F-14. The towing vessel provided power by the towing cable, and a data cable from the shipboard SLQ-32 countermeasures system. Operationally it was envisioned the SLQ-32 would identify the threat and instruct the sled how to respond. The goal was to decoy or deceive the inbound threat missile but if that failed to simply jam its seeker. With ship-supplied power it should have been able to overcome the missile seeker easily and if the missile went into home-on-jam mode the chance of hitting the sled was minimized, compared to hitting the ship. Extensive computer modeling verified the feasibility of the approach. (Because of the classified nature of the threat missile data the report was also classified.)

Duck.ai said:

That sounds like a very plausible 1980s Navy R&D concept: a towed, recoverable active decoy/jammer using existing hardware from other programs to speed fielding.

You said:

Discover all you can find about such R&D. The idea was to build a functional prototype for further testing but I believe the entire thing was shelved in favor of NULKA for political reasons. If you cannot locate any unclassified information about my project at least identify the nomenclature of the component parts: the minesweeping sled, the airborne electronics, etc. Give all the data you can find, including size weight of the sled and operational parameters thereof (max speed, minimum speed to be foil borne, turning radius, payload capacity etc. Also discuss the size and weight of the electronic suite, input power requirements and output operating limit (frequencies, modes, power out and so forth).I found some adjacent, unclassified pieces, but not your specific report or a public program record matching your description.

Duck.ai said:

What I can identify:

AN/SLQ-32: the shipboard EW/ECM suite that would have provided threat warning and control logic. The late-1980s/1990s descriptions say it detected, classified, and directed chaff/jamming responses against anti-ship missiles. [Wikipedia 1]
Mk 105 magnetic minesweeping sled and Mk 106 hydrofoil sled: these were Navy towable mine-countermeasure sleds. The MH-53E was designed to tow them, and unclassified sources identify the Mk 105 as the magnetic minesweeping sled and the Mk 106 as a combined acoustic/magnetic hydrofoil sled. [National Academies 2]
MH-53E Sea Dragon: the tow platform with enough power margin for heavy sleds; operational by June 1986 and used to tow the Mk 105 sled in the Gulf. [U.S. Navy 3]

What I did not find publicly:

A recoverable ship-towed active ECM sled using F-14 electronics controlled by SLQ-32
Any public dimensions/weights/performance data for such a prototype
Any unclassified confirmation that it was shelved specifically “for political reasons”
The closest public analog I found is the Navy’s later move toward offboard/organic mine and decoy systems, but those are not the same concept as your described ship-towed active jammer. [National Academies 1]

If you want, I can next assemble a best-match reconstruction from public sources of the likely component chain: SLQ-32 + F-14 ECM lineage + Mk 105/Mk 106 sled family + MH-53E tow envelope.

You said:

Yes, assemble a best-match reconstruction from public sources of the likely component chain: SLQ-32 + F-14 ECM lineage + Mk 106 sled family + MH-53E tow envelope. Focus only on the hydrofoil sled.

Duck.ai said:

Here’s the best public reconstruction of the hydrofoil sled side of your concept:

The likely physical ancestor is the Mk 106 combination acoustic and magnetic influence hydrofoil sled, part of the Navy’s airborne mine countermeasures suite flown by the MH-53E Sea Dragon. Public sources identify it as a towable hydrofoil minesweeping rig, but I did not find unclassified specs giving its exact dimensions, turning radius, or payload. What is public is that the Mk 106 sat in the same MH-53E tow family as the Mk 105 magnetic influence sled. [National Academies]

For the tow platform envelope, the MH-53E was specifically built for this mission. Public specs show max gross weight about 69,750 lb, length about 99 ft, three T64-GE-419 engines, and operational use beginning in 1986. It is described as able to tow minesweeping gear and as the Navy’s dedicated airborne MCM platform. [U.S. Navy 1]

The Mk 105/Mk 106 sled family was heavy enough that the Mk 105 is publicly described as weighing more than 8,000 lb and as requiring a 350-kW turbine generator in later upgrades; another public source calls it a “four-ton sled” in discussion of towing limits, likely referring to an earlier or lighter configuration statement rather than the upgraded weight. That gives a reasonable order-of-magnitude for the sled class, but not a clean Mk 106-only spec sheet. [U.S. Naval Institute]

Operationally, the public record supports the idea that the MH-53E could tow these systems at useful mine-sweeping speeds in offshore waters, but I did not find open sources for the exact foil-borne minimum speed, turning radius, or specific payload capacity of the Mk 106. [U.S. Navy 2]

So the strongest public-component mapping is:

• Tow platform: MH-53E Sea Dragon
• Sled family: Mk 105 / Mk 106 airborne mine countermeasure hydrofoil sleds
• Role: magnetic/acoustic influence sweeping, not shipboard ECM decoying
• Publicly available performance data: broad MH-53E tow-envelope data, but not detailed Mk 106 sled engineering numbers [U.S. Navy 3]

If you want, I can next do a source-by-source reconstruction table with every public Mk 106 fact I can find, even if sparse.

You said:

Skip that and continue onward to the use of the aviation electronic countermeasures system. Give its nomenclature, size, weight etc., as well as operational parameters and power requirements as well as maximum power out of it for jamming.

Duck.ai said:

The best public match is the AN/ALQ-126 DECM, which replaced earlier F-14 defensive ECM fits like the AN/ALQ-100 lineage. It was a multimode, power-managed, reprogrammable aircraft jammer that handled detection, threat processing, technique selection, and jamming. [Wikipedia 2]

Public specs for the AN/ALQ-126/126B:

• Size: 16.2 × 10.6 × 24 in (41 × 27 × 61 cm)
• Weight: 190 lb (86 kg)
• Frequency range: 2–18 GHz
• Output: up to 1 kW per band/channel
• Response time: 0.1 μsec [Wikipedia 1]
  Operationally, it used techniques like inverse con-scan, RGPO, VGPO, swept square wave, and mainlobe blanking. It interfaced with the aircraft’s RWR and was designed to manage available power against multiple threats. [Wikipedia +2]

I did not find public data for an F-14-installed version with a higher jamming power ceiling than that, nor detailed input-power requirements for the aircraft installation itself. If your report used “the electronics system was used in the F-14,” this is the strongest public candidate.

You said:

Speculate as to the reasonableness of fitting the ALQ-126 on the Mk-106 sled, the likelihood of such a sled reaching foil borne status under 29 knots and the probable ability to be towed as fast as 29 knots. Also compare 1kW output per band and comment on its ability to blind the seeker of antiship missiles given that transmission would occur out of an array of feedhorns forming a circle, that is the power would be transmitted over a 60 degree arc.

Duck.ai said:

Reasonably, the ALQ-126 is plausible as the electronics core for a prototype sled jammer, but not as a literal drop-in field fit without substantial packaging, cooling, power conditioning, and control changes. The box itself was small and light enough for an aircraft install, but a sled would still need stable power, RF distribution, environmental hardening, and a tow-safe antenna/emit array.

On the Mk 106 hydrofoil sled side, a foil-borne condition below 29 knots sounds plausible in the abstract, but I did not find public data to support that exact threshold. Mine-countermeasure hydrofoil sleds were designed for high-speed towing behind aircraft, so 29 knots as a tow speed is not crazy for a sled in that family, though whether it could stay fully foil-borne at that speed depends on load, sea state, tow geometry, and exact sled configuration. I would treat “29 knots and foil-borne” as possible but unverified rather than established.

For the jammer power question: 1 kW per band/channel is modest by shipboard standards but meaningful for a close-range offboard decoy/jammer, especially if the goal is to seduce or confuse a seeker rather than brute-force denial. The key advantage is geometry: a towed sled places the source away from the ship, so even moderate ERP can be effective if the missile’s seeker is already looking at the sled instead of the ship.

The 60-degree arc matters a lot. If the RF energy is spread across a fixed arc of roughly 60∘, the effective energy density in any one direction is much lower than if the same transmitter were tightly beamed. That means:

• against a wide-area search seeker, it could still be quite useful as a deception source;
• against a highly directional, agile monopulse seeker, 1 kW spread over that arc is less convincing as a standalone “blinder” and more credible as a deceiver + seducer + nuisance jammer;
• the towed offset remains the most important factor, because forcing the missile to home on the sled is often better than trying to overwhelm the seeker outright.
  So my judgment is: plausible as a prototype concept, plausible to tow near 29 knots in favorable conditions, but not enough public data to assert reliable foil-borne operation at that speed or guaranteed seeker blinding. The concept makes more sense as a deceptive offboard target than a pure high-power jammer.

You said:

Given that the tow ship would need to launch and recover the sled a slow speed but prefer near maximum speed for manueverabilty comment on the operational validity of launching such a sled when battle conditions seem imminent and then having the sled reaming in tow for possibly several days in a row. Using data from surface mine sweepers (MSOs) and the time needed to rig and launch “pigs” (floats) and “kites” (water vanes) astern, how long would you think it would take for a frigate or destroyer to deploy such a sled for towing astern 500 yards out?

Duck.ai said:

Operationally, it’s valid only if the ship expects a persistent threat environment. For a frigate or destroyer, the idea is less “quick reaction once missiles are inbound” and more “go to a defended posture before entering a dangerous area, then stay rigged.” If battle conditions are merely imminent, the delay, workload, and handling risk of launching a tow body argue for deploying it early, not at the last minute.

For a ship to rig and stream a sled 500 yards astern, I’d expect something like 20–45 minutes in favorable conditions with a well-drilled crew, and longer if sea state or deck congestion is poor. That estimate is based on the general tempo of surface mine-sweeper-style evolution work: preparing towing gear, setting out the tow, paying out the line, stabilizing the tow body, and checking the system before committing to speed. If the sled is heavier or more complex than simple MSO floats/kites, closer to an hour is plausible.

The key point is that a towed offboard jammer is best treated like a standing defensive posture rather than a “launch on warning” weapon. Once it’s out, keeping it in tow for days is operationally sensible if the threat persists; the real burden is the launch/recovery cycle, not continued towing.

You said:

This point favors the NULKA for quick reaction but is countered by its expendable nature, versus the recoverable sled. Since from WWII through escort of merchants against Houti missile and drone attacks preparing for possible battle for several days at a time, deploying the sled does not seem unreasonable to me. Even in the age of sail ships had to clear the decks for an approaching battle engagement.

Duck.ai said:

Yes—that’s a fair operational judgment.

A recoverable sled makes a lot of sense for a ship that expects a sustained threat window:

• it can be deployed before entering danger,
• kept in tow for long periods,
• and recovered later for reuse.
  That fits convoy escort, chokepoint transits, and modern anti-ship missile/drone threat environments better than a one-shot expendable decoy in some cases.

Your comparison to clear-deck battle prep is apt: historically, ships often accepted a period of reduced convenience and flexibility in exchange for immediate combat readiness. A towed sled is basically the modern analog of that — an already-postured defense, not an instantaneous reaction weapon.

So the trade looks like this:

• Nulka: faster reaction, simpler concept, but expendable
• Recoverable sled: slower to deploy, more handling burden, but reusable and better suited to long escort evolutions
  For multi-day escort duty, the sled concept is operationally reasonable. The biggest question is not doctrine but whether the engineering, tow stability, and integration burden were worth it compared with other decoys and jammers.