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Identifying Warships

Recognition as a way of life

As intelligence professionals, we are often called upon to be able to differentiate pieces of military hardware, or to be able to teach other non-intelligence professionals, such as aircrew, how to do so. While seemingly a trivial task, the consequences for getting it wrong can be quite catastrophic. In April 1994, two US Air Force F-15 fighters shot down a pair of US Army Blackhawk helicopters, killing 26 friendly personnel. Although many failures contributed to the incident, subsequent investigation noted that inadequate visual recognition training was a significant contributing factor.

Figure 1. A US Army UH-60 Blackhawk similar to the ones shot down in the 1994 incident. The stub wings and fuel tanks were removable; typical aircrew training did not include these features. When fitted, these features caused the aircraft to resemble Mi-24/HIND and Mi-17/HIP helicopters operated by Iraqi forces. Incomplete training can be as bad as no training at all. [Blackhawk photo] DoD photo by: SrA Gudrun Cook; retrieved from Wikimedia Commons on 28 Jan 2015.

Although it may seem like an intuitive process, in order to consistently train people on recognition, we have systematized it. The current standard for visual recognition (commonly termed vis (viz)- ()recce (reckee)) is called Total Form Concept (TFC). This system breaks a whole system into characterizable parts, giving us a common lexicon with which to describe the equipment. The system changes based on the type of equipment being describedobviously, an airplane doesnt have the same parts as a tank, which is very different from a ship. The various sub-systems of TFC are known by the following mnemonic aids:

Mnemonic

Expansion

Usage

WEFT

Wings, Engine, Fuselage, Tail

Airplanes

REFT

Rotors, Engine, Fuselage, Tail

Helicopters

HATS

Hull, Armament, Turret, Suspension

Ground Vehicles

HAMS

Hull, Armament, Masts, Silhouette

Surface Ships

SaS

Sail, Silhouette

Submarines

This bulletin will examine the HAMS system for describing surface vessels. You may also see this system described as MASH, with the same components.

Parts of a warshipHull

The hull of a ship is its key feature. It is literally the foundation that the rest of the ship is based on. It is important to note that while the hull includes everything from the main deck down, when discussing ship recognition, we are typically only concerned with the hull down to the waterline.

One of the most important questions in describing hulls today is one that formerly was a mere afterthought: how many hulls are there? Where a century ago, nearly every warship had just one hull, the reality today includes one-, two- and even three-hulled vessels.[footnoteRef:1] [1: Two-hulled ships are called catamarans while three-hulled ships are trimarans.]

The type of hulls are also important. Most major warships have full-displacement hulls, which displace a given amount of water both at rest and in motion. Some smaller craft may have semi- or full-planing hulls, which rise out of the water at high speed. Special cases include hydrofoils, which have wings that fly just beneath the surface, allowing the ship to travel at extremely high speed, air cushion vehicles (hovercraft and surface effects ships) which have full or partial skirts that trap a cushion of air for the ship to ride on, and the SWATH, or Small Waterplane Area Twin Hull, which fully submerges the hulls under water, only breaking the surface with struts connecting to a platform well above. While slow, these ships are incredibly stable.

The shape of the hull can be defined in terms of its three dimensions: plan form (shape as seen from above), cross-section (seen from front), and profile (seen from the side).

Planform:

Overall shape: Is the planform symmetrical (fore-aft or port-starboard) or does it have different shape on one side or another?

Taper: How hard does the hull taper at either the bow or the stern? Fast moving ships may have more aggressive tapers than slower auxiliaries, which may appear blunt

Cross-Section

Vee or Tumblehome: Hulls that taper toward the waterline can be said to have vee while hulls that taper away from the waterline have tumblehome[footnoteRef:2] [2: Tumblehome was an extremely common design feature in the late Nineteenth Century, all but disappearing in the twentieth. However, the design process for the US Navys new Zumwalt-class destroyers resurrected it, finding that it has excellent stealth properties.]

Knuckle: If there is a noticeable change in angle as the hull moves to the waterline, the hull has knuckle

Profile:

Deckline: Is the main deck an unbroken line (flush) or are there multiple deck levels?

Sheer: Does the deckline slant noticeably from bow to stern?

Freeboard: Does the ship show a lot of hull above the waterline, or does she sit low in the water?

The bow (also known as a stem) and stern also can provide key clues for visual recognition. In reality, these are integral parts of the three features previously discussed, but their distinctive positions at the extreme ends of the ship mean that they can be taken as very important features in their own right. Both can be distinguished by a few common factors:

Degree of curvature in profile: Does it cut a straight line to the waterline, or is there curvature?

Direction of curvature in profile: If it curves, does form an inward or outward curve?

Shape in plan form: In modern warships, even the bluntest bow is typically extremely pointy, but some take this to an extreme: The Iowa-class battleships were known for extremely narrow bows. Sterns may vary much more, from a sharp point, to a gentle curve, to a truncated square stern.

Figure 2 Bows and Sterns [Bow & Stern graphic] Author; Original Work

Key questions:

1. How many hulls does the ship have?

2. What kind of hull(s)?

3. How is the hull shaped?

4. What are the bow and stern shaped like?

Armament

In the 1940s, this was easy. Warships typically had a few big guns, mounted in turrets, and a few smaller guns, which also may have been mounted in turrets. Perhaps they had some prominent torpedo tubes as well. The 1950s brought guided missiles, then in the 1980s, the missiles began hiding in recessed launchers below deck. Some advanced designs even hide their guns when not in use, to reduce radar signatures. All this makes classifying armament much more difficult.

Guns

Most warships still carry guns. Some special purpose ships can also carry howitzers or mortars.[footnoteRef:3] Guns are typically found in one of two configurations: [3: Guns are long-barrel weapons that primarily provide high-velocity, low-angle, direct fire. Mortars are short-barrel weapons designed to provide high-angle, low-velocity, indirect fire. Howitzers are somewhere between these two, designed to provide both direct and indirect fire with their mid-length barrel. ]

Turret: A turret is a complex structure that includes both the guns (typically, but not necessarily always, with an enclosed gunhouse) above deck, and associated magazines and handling rooms below deck.

Mount: A mount is a self-contained structure that includes only the gun and its associated training and elevating mechanisms. Typically a mount has ready use lockers for ammunition in place of the turrets handling facilities.

While it may seem somewhat pedantic to rigidly differentiate the two, especially given the fact that you cant tell what facilities are below deck, when known, these distinctions should always be applied. The crucial questions are always:

1. How many mounts or turrets?

2. How many guns in each?

3. What caliber of gun?

These questions should be answered for at least the largest caliber guns on the ship, and preferably any guns over 3 (76mm). In older, all-gun warships, it was common to have both a large primary armament, and a smaller secondary armament. When describing naval artillery, both the size of the bore and the length of the barrel are given, in the following format: 16/50 caliber, or simply 16/50. While the term 50 caliber may be confusing for those familiar with the 12.7mm or 0.5 inch caliber of small arms, here it refers to the length of the barrel. This weapon (the main armament for the Iowa-class battleships, had a bore of sixteen inches, and a barrel length of fifty times the bore, or 800 inches.

Torpedoes

In terms of vis-recce, torpedoes range from irrelevant (the Spruance-class destroyers of the 1970s carried theirs behind sliding doors in the hull) to obscure (the succeeding Arleigh Burke-class carries theirs on deck, but the tubes are small and hard to see.) For smaller torpedo-armed fast attack craft, they are quite prominent, however, as they typically take up much of a small crafts deck space. Once again, there are a few key questions:

1. How many torpedoes?

2. What type of torpedoes?[footnoteRef:4] [4: Modern torpedoes tend to be either for anti-surface or anti-submarine work. Anti-surface torpedoes tend to be noticeably larger than their dedicated anti-submarine counterparts.]

3. Single or multiple mounts?

4. Fixed or trainable mounts?

Missiles

From the 1950s, warships began carrying guided missiles. These increasingly supplanted guns, until for a time during the 1960s, ships were built with missile-only armament. Today, this is rare, as the medium-caliber gun gives a great deal of versatility to a ship. Missiles are, however, a major part of the armament of modern warships.

Missile-armed ships display various types of launchers:

Canister or tube launchers: Like it says on the tin, these usually resemble torpedo tubes set at an angle, these launchers are usually fixed in place.

Arm-type launchers: The arms are launch rails which provide a steady platform for launching missiles. These come in both one- and two-arm variants.

Box launchers: Again, fairly self-explanatory, instead of individual canisters, the missiles sit in individual cells in a box. Unlike canister launchers, these can typically be aimed. A special case are vertical launch systems. These are fixed box launchers recessed in a deck or a deckhouse.

Aircraft

Some sources include aircraft facilities under Silhouette. While the case can be made for it, aircraft are, properly, weapons. After all, they are the primary armament of the aircraft carrier, and the outer zone antisubmarine weapon for destroyers and frigates. The key questions:

1. What type of deck? Full-deck (like an aircraft carrier) or just a helicopter pad?

2. Are there obvious support facilities? (Elevators to a hangar deck, doors to a hangar bay)

Masts

Masts are tower-like structures that hold everything from signal flags to electronic equipment. Typically, modern warships will have either one or two masts. When only one is present it is perfectly proper to just say the mast. When two are present, the forward mast is the foremast, while the after mast is the mainmast.[footnoteRef:5] [5: This is a holdover from the Age of Sail. On three-masted sailing ships, the masts were the foremast, mainmast, and mizzenmast. On two-masted ships, the mizzenmast was omitted. This was carried over to the Steam Age.]

Masts come in a number of forms. Pole masts are perhaps the simplest, but there are also tripod (as well as other multi-leg configurationsthe Imperial Japanese Navys Nagato-class battleships had a hexapod mast!) In addition, there are lattice masts, macks (combined mast and smokestacks), and the newest variation, the stealthy enclosed mast.

Electronics can also be included in this category. For example, radar antennae not mounted on a mast can be included as part of masts, despite the fact that they are not, technically speaking, masts. These can be either mounted on small pedestals, or can be fixed arrays mounted directly on faces of the superstructure.

Figure 3 USS Spruance (DD-963); note blocky superstructure. [Spruance photo] US Government photo by PH2 Michael Sandberg; retrieved from Wikimedia Commons 29 Jan 15

Note: Similar ships may be differentiated solely by the superstructure in some cases: the US Navys Spruance-class destroyers had a very blocky superstructure, while the Ticonderoga-class cruisersbuilt on the same hullhave a roughly similar superstructure, but with large angular additions toward the top, bearing the planar-array radars.

Figure 4 USS Ticonderoga, CG-47, note high, angular structures bearing planar phased array radars. [Ticonderoga photo] National Archives photo by Bruce Trombecky; retrieved from Wikimedia Commons, 29 Jan 15

Remember that certain weapons systems may be associated with certain, sometimes very distinctive electronics. These range from acquisition radars to fire control directors.

Key questions:

1. How many masts are there, and where are they mounted?

2. What types of masts are they?

3. Are there any prominent pieces of electronics on the masts?

4. Are there any prominent pieces of electronics not on the masts?

Silhouette

The S in HAMS has, in the past, been referred to as stacks (smokestacks) or superstructure. The current term, silhouette, encompasses those two items, but is much broader. Essentially, it includes any significant feature that is not included under hull, armament, or masts.

The superstructure is any permanent structure above the main deck level. This typically includes space for the bridge, trunking for exhaust uptakes, and other spaces such as helicopter hangars. It may have very distinctive features, however.

Is the superstructure blocky, or angular?

Tall or short?

Are there two distinctive structures, or is there a single deckhouse?

This also includes the smokestack (stack, or more properly, funnel) which serves as an exhaust for the propulsion system. Most ships will have some form of visible exhaust, although nuclear-powered ships typically do not. However, there are always exceptions. The Russian nuclear-powered cruiser Petr Velikiy has boilers in addition to her reactor, requiring uptakes. Similarly, some diesel or gas-turbine powered craft may vent their exhaust at or near the waterline, resulting in no distinctive funnel. The questions to ask about the funnels are:

How many are there?

What shape are they? Funnels may be simple tubes, or may have a cap at the top. Some smaller steam-powered ships may have their funnels trunked outside the hull, resulting in distinctive shapes.

Where are they? Typically, multi-funnel ships have their funnels aligned on the centerline; ships have also had side-by-side and en echelon arrangements.

What do I call it?

Ultimately, the decision on how to classify a ship rests with the operator. Since the 1920s, the United States Navy has had a relatively consistent system of classifying their ships. Other navies have similar systems. As an example of how difficult using native designators could get, consider the following table of designations for the ship type known as Destroyer in Anglophone navies.

Ship type

Meaning

Abbrev.

Used by

Destroyer

Shortened form of Torpedo boat destroyer

DD

US Navy, most British Commonwealth navies

Bol'shoy Protivolodochny Korabl'

Large anti-submarine ship

BPK

Soviet Navy/Russian Navy

Kuchikukan

Expulsion (lit. driving away [the enemy]) Ship

--

Japan (Imperial Japanese Navy, pre-1945 above; Japanese Maritime Self-Defense Force, post-1945 below)

Goeikan

Escort (lit. protection) Ship

--

Guchugham

Protector (also means babysitter)

--

Republic of Korea Navy

Qzhjin

Pursuit Ship

--

Peoples Liberation Army Navy (Peoples Republic of China)

Zerstorer

Destroyer

--

German Navy

Contretorpilleur

Anti-torpedo boat

--

French Navy

Cacciatorpediniere

Torpedo-boat hunter

--

Italian Navy

Torpedobootjager

Torpedo-boat hunter

--

Dutch Navy

Obviously, using all these designations to refer to ships would be impractical. For purposes of intelligence reporting, however, the United States and her allies have standardized on a system similar, but not identical to the USNs classification system. This system is spelled out in the Glossary of Naval Ship Types.

UNCLASSIFIED

Types of BowsStraight BowOutward Curved (Icebreaker or Italian) BowRaked BowInward Curved (Clipper) BowTumblehome Bow (May also have curve)Types of SternsTransom SternCruiser SternRaked SternCurved SternTumblehome Stern (May also have curve)

Types of BowsStraight BowOutward Curved (Icebreaker or Italian) BowRaked BowInward Curved (Clipper) BowTumblehome Bow (May also have curve)Types of SternsTransom SternCruiser SternRaked SternCurved SternTumblehome Stern (May also have curve)