A hatch is basically a door that is installed on a horizontal plane (such as in a floor, a paved lot, or a ceiling), instead of on a vertical plane (such as in a building wall). Hatches are usually used to provide access to assets that are either located underground (such as hatches to basements or underground storage areas), or to assets located above ceilings (such as emergency roof exits). At water and wastewater facilities, hatches are typically used to provide access to underground vaults containing pumps, valves, or piping, or to the interior of water tanks or covered reservoirs. Securing a hatch by locking it or upgrading materials to give the hatch added strength can help to delay unauthorized access to any asset behind the hatch.

Like all doors, a hatch consists of a frame anchored to the horizontal structure, a door or doors, hinges connecting the door/doors to the frame, and a latching or locking mechanism that keeps the hatch door/doors closed. A general discussion of door security is provided in the Security for Doorways - Side-Hinged Doors Product Guide. This Guide focuses on the unique aspects of hatches relative to standard doors, and focuses on security features that are available to specifically protect hatches at water and wastewater facilities from various threats.

It should be noted that improving hatch security is straightforward, and that hatches with upgraded security features can be installed new or they can be retrofit for existing applications. Many municipalities already have specifications for hatch security at their water and wastewater utility assets. For example, Detroit, Michigan; Greenville, North Carolina; Louisville Municipal Sewer District; and the City of Marysville, Washington, require that hatch doors be installed with standard hardware for the implementation of padlocks. Specifications for hatch security can be found on these municipalities' websites.

Depending on the application, the primary security-related attributes of a hatch are the strength of the door and frame, its resistance to the elements and corrosion, its ability to be sealed against water or gas, and its locking features. These features are described in more detail below.

Hatches must be both strong and lightweight so that they can withstand typical static loads (such as people or vehicles walking or driving over them) while still being easy to open. In addition, because hatches are typically installed at outdoor locations, they are usually designed from corrosion-resistant metal that can withstand the elements. Therefore, hatches are typically constructed from high gauge steel or lightweight aluminum.

Aluminum is typically the material of choice for hatches because it is lightweight and more corrosion resistant relative to steel. Aluminum is not as rigid as steel, so aluminum hatch doors may be reinforced with aluminum stiffeners to provide extra strength and rigidity. The doors are usually constructed from single or double layers (or "leaves") of material. Single-leaf designs are standard for smaller hatches, while double leaf designs are required for larger hatches. In addition, aluminum products do not require painting. This is reflected in the warranties available with different products. Product warranties range from 10 years to lifetime.

Steel is heavier per square foot than aluminum, and thus steel hatches will be heavier and more difficult to open than aluminum hatches of the same size. However, heavy steel hatch doors may have spring-loaded, hydraulic, or gas openers or other specialized features that help in opening the hatch and in keeping it open.

Many hatches are installed in outdoor areas, often in roadways or pedestrian areas. Therefore, the hatch installed for any given application must be designed to withstand the expected load at that location. Hatches are typically sold to withstand either pedestrian or vehicle loading. Pedestrian loading hatches are typically designed to withstand either 150 or 300 pounds per square feet (psf) of loading. The vehicle loading standard is the American Association of State Highway and Transportation Officials (AASHTO) H-20 wheel loading standard of 16,000 lbs over an 8 inch by 20 inch area. It should be noted that these design parameters are for static loads and not dynamic loads; thus, the loading capabilities may not reflect potential resistance to other types of loads that may be more typical of an intentional threat, such as repeated blows from a sledge hammer or pressure generated by bomb blasts or bullets.

The typical design for a watertight hatches includes a channel frame that directs water away from the hatch. This can be especially important in a hatch on a storage tank because this will prevent liquid contaminants from being dumped on the hatch and leaking through into the interior. Hatches can also be constructed with gasket seals that are air-, odor-, and gas-tight.

Typically, hatches for pedestrian loading applications have hinges located on the exterior of the hatch, while hatches designed for H-20 loads have hinges located in the interior of the hatch. Hinges located on the exterior of the hatch may be able to be removed, thereby allowing intruders to remove the hatch door and access the asset behind the hatch. Therefore, installing H-20 hatches even for applications which do not require H-20 loading levels may increase security, because intruders will not be able to tamper with the hinges and circumvent the hatch this way.

In addition to the location of the hinges, stock hinges can be replaced with heavy duty or security hinges that are more resistant to tampering. More information on security hinges can be found in the Security for Doorways - Side-Hinged Doors Product Guide.

The hatch locking mechanism is perhaps the most important part of hatch security. This section discusses locks that can be implemented for hatches; however, more in depth discussion on different types of locks, lock terms, and lock vendors is available from the Locks Product Guide.

There are a number of types of locks that can be implemented for hatches, including:

Slam locks are internal locks that are located within the hatch frame. These locks are similar to typical door locks, in that a spring-loaded latch retracts into the hatch door when the hatch door is being closed. The spring is released when the hatch is shut all the way, extending the latch from the hatch door behind the hatch frame. Because the latch catches on the hatch frame when someone attempts to open the hatch, the hatch door is secured. The hatch can only be opened when the correct key is used to retract the latch from behind the door frame. A standard key consists of a square metal head; however, other types of heads with more complex configurations can be implemented to add security to this type of lock.

A cylinder lock (the typical door lock that is opened using a key) can be placed within a recessed box welded to the hatch cover. The cylinder lock must then be unlocked with the appropriate key before the hatch can be opened. Standard cylinder locks are difficult to bypass or pick and provide good security. Advanced cylinder locking security is also available. For example, the Bilco Company markets a recessed cylinder lock with a threaded cover plug. The cover plug must be unscrewed before the key can be put into the cylinder lock, disguising the lock and preventing it from accumulating dirt or grime.

Bolt locks are bolts that are screwed into holes drilled through the hatch cover and frame, securing the hatch to the frame and preventing it from being opened unless the bolts are first removed. Several types of bolt locks are available. The basic bolt lock has a hexagon-shaped head and can be removed with standard bolt removal tool (tire iron, etc.). USF Fabrication also markets a higher security penta-head bolt; this bolt cannot be removed with standard bolt removal tools. Finally, McGard, Inc. manufactures a specialized bolt that requires a specialized key lock to remove.

Hatches can also be designed with several different features to accommodate padlocks. The hatch cover can be modified with a slot that closes over a raised pin anchored to the hatch frame. A padlock can then be inserted through a hole at the top of the pin so that the hatch door cannot be lifted past the padlock (the "staple for padlock" shown in the Figure.) This same type of mechanism can be designed to be recessed within the hatch frame so that the pin doesn't protrude above the frame. This configuration makes it more difficult to reach the lock with a bolt cutter or pliers. A hasp and shackle-type lock could also be implemented on the outside of hatch doors. In a typical hasp and shackle application, a half circle of hardened steel is bolted to the top of the hatch, and then a slotted, hinged metal arm is bolted to the hatch frame. The slot in the hinged metal arm is placed over the loop on the hatch door, and a padlock is placed through the loop, locking the hatch down. Finally, the hasp and shackle for the padlock can be placed in a recessed compartment welded to the hatch. The compartment typically has its own cover. This hides the padlock and reduces the potential for crimes of opportunity. It also makes it more difficult to reach the padlock, which can make it more difficult to cut.

These locks vary in complexity, security, and their ability to be retrofit into existing hatch covers. The more basic locking devices, such as the hasp and shackle-type lock, can be added to an existing hatch door by the owner simply by drilling holes into the hatch cover and the frame, purchasing a hasp and shackle system, anchoring it to the hatch, and then placing a padlock through it. Adding a staple for a padlock would also be straightforward. However, modifying an existing hatch door and frame to add a recessed cylinder lock, a recessed staple for a padlock, or a slam lock, may be more difficult.

The security of these different lock types also varies. A hasp and shackle-type lock is the least secure because it may be able to be unbolted from the cover or frame, or the padlock may be able to be cut with bolt cutters. A staple for a padlock would have similar problems with potentially cutting off the padlock, although it would not be able to be unbolted from the hatch. Bolt locks would be considered more secure, although a determined intruder may be able to remove them. A facility could enhance the security of a bolt lock by using a head-shape that is hard for a pair of pliers or a socket to grip. Slam locks provide more security than do raised padlocks and bolt locks, although these types of locks may have some of the same vulnerabilities as bolt-type locks because the entire lock enclosure may be able to be turned and opened this way. Putting a cover over the lock enclosure will enhance the security of these types of locks. Locks which are recessed within the hatch lid (recessed staples for padlocks and the recessed cylinder lock) are the most secure locks for a hatch cover because they require special keys and they are difficult to access. For example, a padlock on a recessed staple is much harder to defeat than is a padlock on a protruding staple.

In addition to locks that are supplied by the vendor with a hatch, many municipalities are designing their own solutions for securing hatches. Two examples are provided. In the first graphic, removable iron bars are inserted through heavy-duty eye hooks anchored into the ground or the hatch frame, and then through eye hooks anchored to the hatch doors. A hole is drilled through the one end of the iron bar and a padlock is inserted through it, preventing the bar from being pulled through the eye hooks. The other end of the bar is shaped into a curve so that the bar cannot be pulled through the eye hooks from that direction. The iron rods are located just above the hatch doors, blocking them from being pulled upwards and thus preventing them from being opened. Thus, the padlock and the bars must be removed before the hatch can be opened. In the second example, a section of a pipe has been welded as a cover over the padlock. The pipe has openings on the sides for personnel to reach down through the pipe to open the lock, but the pipe is sealed at the top, preventing persons with bolt cutters from reaching the lock down through the top of the pipe.

It should be noted that the security of a hatch will only be as strong as the weakest part of its security system. For example, using a recessed staple-type lock, but securing it with a weak padlock, will not provide a high level of security. Similarly, if a hatch does not have heavy duty hinges or hinges with protected hinge pins, even high security locks will not provide adequate security because the hatch can be accessed by removing or damaging the hinges.

Several manufacturers have developed products that can be retrofit into existing hatch covers to provide additional security to the hatch. One type of hatch security lock consists of an industrial grade steel bar that is installed over an existing hatch. Plates are anchored in the ground or in the floor on either side of the hatch, and the steel bar is attached to one plate with a hinge that allows it to fold down over the hatch or up and away from the hatch. A second hinged post with a hole drilled through it for a padlock is installed on the opposite side of the hatch. When the steel bar is closed over the hatch, it fits over this second hinged post and prevents the hatch door from being lifted up. The bar can be locked to the post using a padlock (standard design) or a keyed cylinder lock (custom design). A shield plate installed at the end of the bar covers the lock so it can only be reached from the bottom. This hides the lock from view and also makes it more difficult to reach, increasing the security of the Hatchlok™. Other optional features include additional bars fastened to the main bar that criss-cross the hatch to provide more coverage over the hatch.

Another hatch locking system consists of a spring-loaded lock that is installed on an existing hatch. To install the lock, a hole is drilled into the hatch cover close to the hatch edge, and a lock "receiver" is attached to the underside of the hatch cover. The specialized lock is then fitted through the hole in the hatch and through the receiver. Then a bolt head at the top of the specialized lock is pressed, releasing a lever arm, which then catches on the underside of the hatch frame, locking the hatch to the frame. Tightening the anchor bolt tightens the Stabiloc™ against the hatch frame. A special bolt key is used to release the lock.

Fire resistant and fire proof hatches are specially manufactured to resist burning and/or to reduce the temperature increase on the side of the hatch away from the fire. They are typically implemented to prevent a fire from spreading from within an area protected by a hatch. Resistance to burning is usually given as the number of minutes that it would take a hatch to burn under standard conditions (for example, a hatch with a 20-minute fire rating would take 20 minutes to burn, while a hatch with a 90-minute fire rating would take 90 minutes to burn). These ratings include the fire resistance of the hatch doors, the hatch frame, and the hardware. Evaluations of temperature increases on the side of the hatch away from the fire are indicated as "temperature rise" ratings. The temperature rise rating indicates a maximum temperature rise, above ambient, developed on the unexposed face of the hatch at the 30 minute point of a Standard Fire Test. Thus, a hatch rated for a 250? F temperature rise would only allow the temperature to rise 250? F on the other side of the hatch after 30 minutes, whereas a 450? F temperature rise hatch would allow the temperature to rise 450? F.

There are a number of different associations and organizations that provide fire ratings, including the American Society for Testing and Materials (ASTM), the National Fire Protection Association (NFPA), and the Underwriters Laboratory (UL). Individual tests that may be performed or cited by manufacturers include ASTM E119 (Fire Tests of Building Construction and Materials), NFPA-80 (Fire Doors and Windows), NFPA 251 (Standard Methods of Tests of Fire Endurance of Building Construction and Materials), and UL 10B (Fire Tests of Door Assemblies).

Examples of fire-rated hatches include the Bilco type FR fire rated hatch and the Babcock-Davis B-FCR. The Bilco FR hatch is constructed from single leaf aluminum with an intumescent mastic fireproof coating. This hatch has a two hour fire rating that complies with NFPA 80, NFPA 251, and ASTM E119. The Babcock-Davis B-FCR Series fire rated floor doors contain 4 inches of fire-rated insulation to meet the ASTM E119 standard of a maximum temperature rise to 250? F in 30 minutes and a 2-hour NFPA 251 rating in a floor/ceiling assembly.

One of the other effective means for protecting hatches and vaults is by implementing the correct signage. For example, posting a "No Trespassing" sign that cites any local ordinances against trespassing on the inside of the hatch/vault door will ensure that potential intruders see the posting even if the vault door is already open. In addition, other security hardware, such as hasp protectors/covers, intrusion alarm systems, or other measures could be implemented where warranted.

The primary factors affecting the cost of a hatch are:

For example, a 36-inch by 36-inch aluminum hatch with stainless steel hinges and hardware designed for a normal pedestrian load from Acudor Products, Inc., is approximately $800. The same hatch designed to H20 specifications for vehicle loading is approximately $1,300. Hatches from Bilco, Inc., are similarly priced. The 36-inch by 36-inch aluminum J4-AL hatch designed for pedestrian loading is $740, while the J-AL H20 hatch is $1,730. Similar steel hatches from Bilco are $740 and $1,355, respectively.

As described above, there are also different lock types available for hatches. In general, any lock type can be installed on any hatch type, although staples for padlocks are typically standard on pedestrian hatches and slam locks are standard on many H-20 hatches. The cost of the lock will be proportional to the level of security desired; generally, higher security locks are more expensive than are lower security locks. For example, the addition of a recessed padlock to a hatch would add approximately $70 to the cost of the hatch, while adding a recessed cylinder lock would add approximately $150 to the cost of the hatch. The potential for retrofitting different lock types into existing hatches was discussed under the Hatch Locks subsection above.

The standard Hatchlok™ model is designed for a standard 30-inch hatch and sells for approximately $350. The base model has a staple for a padlock. The base model can be modified to increase the size of the locking bar, add additional bars, or to add a cylinder lock. These modifications will increase the cost of the Hatchlok™.

The Stabiloc™ system (bolt lock plus receiver) costs between $190-$225 depending on the size of the lever arm.

The McGard Intimidator Man-Lock™ bolt-type hatch locks range from about $10.00 per lock for orders over 1,000 to around $20 per lock for orders less than 50. The manufacturer recommends that each hatch be fitted with two separate locks to ensure security. The large key wrench sells for around $40. The manufacturer also makes a smaller key adaptable to a regular socket wrench that costs about $16.50. Keys are available only to registered users.