Water and wastewater utilities have a number of assets that are raised above ground level, including raised water tanks, raised chemical tanks, raised piping systems, and roof access points into buildings. In addition, communications equipment, antennae, or other electronic devices may be located on the top of these raised assets. Typically, these assets are reached by ladders that are permanently anchored to the asset. For example, raised water tanks typically are accessed by ladders that are bolted to one of the legs of the tank. Controlling access to these raised assets by controlling access to the ladder can increase security at a water or wastewater utility.

A typical ladder access control system consists of some type of cover that is locked or secured over the ladder. The cover can be a casing that surrounds most of the ladder, or a door or shield that covers only part of the ladder. In either case, several rungs of the ladder (the number of rungs depends on the size of the cover) are made inaccessible by the cover, and these rungs can only be accessed by opening or removing the cover. The cover is locked so that only authorized personnel can open or remove it and use the ladder. Ladder access controls are usually installed at several feet above ground level, and they usually extend several feet up the ladder so that they cannot be circumvented by someone accessing the ladder above the control system.

Permanent ladder covers usually consist of some type of door that is bolted over the ladder. The door hides the rungs and prevents them from being accessed when the door is closed and locked. To access the ladder, the door is unlocked and then opened, enabling the ladder behind it to be used. Several types of permanent covers are discussed below:

RB Industries manufactures the Ladder Gate, which consists of an 8 foot high by 36 inches wide by 1/8 inch thick aluminum cover that is installed over a ladder leading to a water tank, a raised pipe, or another raised asset. The Ladder Gate has a front and two sides. The front of the Ladder Gate fits over the front of the ladder and covers the rungs, preventing anyone from accessing the ladder from the front. The two sides extend behind the ladder and back to the base of the structure to which the ladder is attached. This prevents anyone from reaching around or behind the Ladder Gate to grasp the ladder. Therefor, although the Ladder Gate does not enclose the entire ladder, it does cover the front and both sides of the ladder for an 8 foot length.

The Ladder Gate's height ensures that intruders cannot reach above it to grasp the ladder. These systems are usually installed above ground level to provide additional height before an intruder could reach an unprotected part of the ladder. For example, by installing a Ladder Gate at 10 feet above ground level, an intruder would have to be 18 feet above ground level (10 feet plus the 8-foot height of the Ladder Gate) to reach the unprotected part of the ladder above the Ladder Gate.

The Ladder Gate is anchored to the ladder frame using 3 brackets that are bolted using galvanized steel bolts. Because the gate's hinge is at the angle between the side and the front of the unit, the hinge is not bolted directly to the ladder frame, which makes the system more secure. Another plate containing an eye bolt is mounted on the other side of the ladder. The side panel opposite the hinge has a slot through which the eye bolt fits when the Ladder Gate is closed. A padlock can then be placed on the eye bolt to lock the Ladder Gate. Depending on how the Ladder Gate is installed, it can be oriented so that it opens to the left or to the right. The system accommodates ladders up to 20 inches wide.

Two manufacturers (Brock Manufacturing and Carbis, Inc.) have designed ladder access controls that consist of a door that is fastened to one side of the ladder frame. When the door is open, the rungs are accessible, and the ladder can be climbed. When the door is closed and locked, the ladder rungs are blocked, and the ladder cannot be climbed. The door is secured by a padlock that locks the handle on the door to a hasp bolted to the ladder frame. Only authorized personnel can unlock the padlock, open the door, and access the part of the ladder behind the door. The Brock product is a 17 gauge galvanized steel door that is 6 feet high and weighs 30 lbs. The door is secured to the ladder frame by upper and lower hinges fastened with 5/16-inch bolts. The bolts are located on the inside of the door so they cannot be removed from the outside. The Carbis doors are also 6 feet high and are available in several materials, including aluminum and mill, primed, galvanized, or stainless steel. Carbis doors weigh from 22 to 56 lbs.

While the Brock and Carbis doors protect access to the front side/outside of the ladder, they do not protect access from the back side of a free-standing ladder. Therefore, these products may be most appropriate for a ladder that is bolted to a wall because the wall prevents access to the other side of the ladder. However, even in the case of a freestanding ladder, access up the back side of the ladder may be blocked from above by the structure to which the ladder provides access.

Serrmi Products, Inc. provides removable protective covers for ladders that it installs on structures designed for the railroad industry. The Serrmi ladder protection device is a 6 foot high aluminum sheet which weighs about 10 lbs and is hung from the upper rung of a ladder. The bottom of the sheet is locked in place using a bar that is placed behind the ladder and is padlocked to the aluminum cover. This prevents the cover from being moved vertically, which prevents it from being slid up and off the top rung from which it is hung. This product is currently manufactured for standard 16 inch-wide railroad industry ladders.

The ladder covers described above can also be used on ladders with safety cages. However, they must be installed above or below the safety cages.

While the products discussed above are installed on existing ladders, Carbis, Inc. has designed a folding ladder that may also be appropriate for purchase and installation for security applications. Although it has primarily been marketed for other purposes (such as fire escape), the Carbis Security Access Ladder can easily be applied to provide protected access to rooftops or other raised assets. The ladder consists of a 12? inch-wide, marine-grade aluminum ladder that is hinged at the rungs so that it can close in on itself from side to side. One side of the ladder is bolted to a wall, and the other side of the ladder frame is folded up against it. To open the ladder, the free (unbolted) side of the ladder is pulled out and down away from the wall, which extends the rungs and moves them from a vertical to a horizontal position. To close the ladder, the free side of the ladder is pushed up and towards the wall, which folds the rungs up against the wall. The entire unit is only 2? inches wide when closed. The units can be secured using a normal padlock, which must be purchased separately. Depending on the ladder's design, the padlock can be installed at the top or the bottom of the ladder. When the ladder is closed and locked, the entire ladder is hidden from view and cannot be accessed. In addition, the closed unit is not easily recognized as a ladder. The unit is available in heights ranging from 9 to 26 feet. Because this unit must be bolted to an existing wall, it may be most appropriate to protect access to a building roof rather than an asset that does not have walls, such as a raised water tank or raised pipes.

The important features of ladder access control are the size and strength of the cover and its ability to lock or otherwise be secured from unauthorized access.

The covers are constructed from aluminum or some type of steel. This should provide adequate protection from being pierced or cut through. The metals are corrosion resistant so that they will not corrode or become fragile from extreme weather conditions in outdoor applications. The bolts used to install each of these systems are galvanized steel. In addition, the bolts for each cover are installed on the inside of the unit so they cannot be removed from the outside.

A discussion of these attributes is provided in Table 1 below.

RB Industries' Ladder Gate is sold by distributors, and costs approximately $750. A padlock to secure the door must be purchased separately. The Ladder Gate can be installed by the purchaser in approximately 1-2 hours. The manufacturer indicates that a team of 2 is typically needed for installation.

Carbis, Inc.'s Security Access Ladder ranges from $340 for the smallest model (shortest ladder) to $732 for the largest model. The Security Access Ladder can be installed by one person in less than an hour. It requires that holes be drilled into the wall on which the ladder will be installed so that the bolts can be anchored. A padlock to secure the compartment must be purchased separately.

The Carbis Security Covers range from $90 to $120 depending on the material. Padlocks are sold separately. The Security Covers can be installed easily by the purchaser.

The Brock Manufacturing Ladder Security Door costs $86. A padlock to secure the door must be purchased separately. Installation of the door is quick (less than one hour), and it can be installed by the purchaser.

The Serrmi ladder lock is currently not sold as a stand-alone product. However, interested parties should contact the manufacturer to discuss options for obtaining the product. The manufacturer indicates that this product is very simple to install and that installation can be done by a single staff person.