6 Opening the doors

6.1          Unstable or poorly packed cargoes may be pressing against the doors which may be forced open when the door gear is released, or the cargo may fall out once the doors are opened.

6.2          The first action for steel doors is to “ring” them which is to tap the flat surface of both doors. If the sound is dull and there is no resonance then it is likely that the cargo will be resting against the door. Extra care should be taken when opening the door.

6.3          If there is a risk that the cargo is resting against the doors or the CTU contains bulk materials, a safety chain can be fitted across the doors, from top to bottom corner fitting (see figure 5.22). This technique can be also used on CTUs without corner fittings by applying a chain from an anchor point on each side or using a shorter chain attached to the locking bars. The length of the chain should be long enough to permit the doors to open but short enough so that the doors cannot open more than 150 mm (6 in).

Figure 5.22 Safety chain

6.4          If a diagonal chain cannot be fitted, then a loose strap across the inner lock rods may be used. If there is no facility for attaching the strap, or strap available the person opening the doors should always open the doors with caution.

6.5          Handles for CTUs vary, some will have one locking bar, others two and the handle design may be a bar or a formed handle, as shown in figures 5.23 to 5.25.

6.6          They may be in the format where the handle is on the same side of the locking rod (see figure 5.26) or between the rods (see figure 5.27).

6.7          Most CTU doors open easily by rotating the handles approximately 90° and then pulling on the handles of locking bars. The action of rotating the bars will mean that the cams push against their keepers and force the door open.

6.8          Figure 5.28 shows the operation of the cams on many freight containers. Rotating the lock rod (A) will cause the breaker surface of the cam to press against the keeper (B), thus forcing the door open (C).

Figure 5.28 Door cam operation

6.9          Once the lock rods have been fully rotated, adopt an upright stance and grasp the lock rods or the door at about shoulder height or just below and pull backwards using the whole body.

6.10        If the doors do not open easily:

• Check that the cams are clear of the keepers;
• Check that the CTU is level and the doors are not binding on the frame;
• Gain assistance to pull the doors open.

6.11        If one door will not open, and the other door may be opened (i.e. the CTU is not carrying a dry bulk tank), then both doors could be opened at the same time which may make opening the doors easier.

6.12        As the door opens be prepared to step back quickly if:

• The contents of the CTU start to fall out; or
• The door appears to be pushing you, not you pulling the door.

6.13        If you need to step out of the way move away from the hinged side of the door.

6.14        Doors in the various types of CTU may open with different degrees of difficulty. The following contribute to this difficulty:

• Corrosion to the door component and hinge pins;
• Damage to the door component, including door gear, or corner post resulting in the misalignment of the hinges;
• Condition of the gaskets, which may not seat properly on the door;
• Racking of the CTU. Many CTUs rely on the doors to hold the rear end of the CTU square. If the CTU is placed on uneven ground the CTU may rack and the doors become misaligned (see figure 5.29).

6.15        Once the doors are free to swing and there is no risk on injury caused by the cargo falling out, walk the doors through 270° and attach the retaining strap to the hook to prevent the door from swinging (see figure 5.30).

6.16        DO NOT ENTER THE CTU YET