How New York Uses and Cares for 101 Metal Ladders
BECAUSE OF THE VARIETY of makes and models of metal aerials now in service, the New York Fire Department has no one instruction manual that covers all. Instead the Division of Training under command of Assistant Chief James T. Ward has issued training bulletins that cover the field operation of each one. In addition, manufacturers provide an operating manual for each model they deliver to the department.
Given the proper care, metal aerial ladders are relatively trouble-free. There are some in New’ York which have been in regular service for 16 years and are still going strong. Key to this proper care lies in the manufacturers’ manuals. Technical Assistant Robert J. Ferris of the Division of Repairs and Transportation strongly recommends that operating personnel become familiar with them. Aside from technical data (provided for shop mechanics) they give considerable information on the everyday operation of the aerial. Daily care and maintenance, minor repairs, how to shift gears, proper placement and angling, safe loading and many others all come within the sphere of the manuals.
Maintenance in quarters
Metal aerials require the same care as all other apparatus. But additional care is required for the moving parts that make up the ladder assembly. This care involves mostly lubrication and inspection and is the responsibility of both the chauffeur and officer. Proper records are kept of all such activities. Although many of the moving parts are self-lubricating, there are some that are not and the operating manuals provide diagrams and instructions for servicing those grease cups or oil holes that require attention.
Since the hydraulic oil tank is the key to the whole operation it should be checked frequently. The apparatus leaves the factory with this tank properly filled and if there is no unusual leakage it should last for a year. However, if the supply drops below the figure recommended in the operating manual, it should be replenished. In any event, a complete change of oil should be made yearly and a drain plug is provided in the bottom of the tank for this purpose. In refilling, transmission oil of the type recommended by the manufacturer should only be used and the oil kept absolutely clean. Minor leaks that develop in fittings can be usually stopped by tightening the connections.
The hydraulic system should be checked frequently and regularly, particularly in units where the ladder receives little use. This can be accomplished by taking the ladder out of quarters and raising it. But in inclement weather, if the ceiling of the apparatus quarters permits, the bed can be raised a few feet and the extensions run out. On some makes there is a test valve but the operation of this valve should be generally left to mechanics.
Both the turntable and the fifth w’heel have grease fittings which require attention once or twice a year. The turntable should be rotated during this operation so that all parts of the ball race are lubricated. For the same reason the truck should be jackknifed in both directions while greasing the fifth wheel. There are other grease fittings and oil holes on all makes but these vary from manufacturer to manufacturer and can only be determined by consulting the appropriate manual.
The ladder should be taken out of quarters frequently, raised and fully extended, and then carefully examined rung by rung. Ladder rollers can develop flat spots, generally from not turning because of lack of cleaning and lubrication. If unnoticed, such flattened rollers can cause serious damage to the affected section. Pulleys and cables should also be examined. If needed, all should receive an application of light engine oil.
As required, but at least every six months, the ladder slides should be lubricated with a thin film of waterresistant grease. Before this grease is applied, the ladder should be extended, and the old grease and grime washed off with a solvent. During freezing weather, a more liberal application of grease should be applied to retard ice accumulation.
Bolts that hold the turntable to the platform present another and most critical inspection point. On some makes they have a tendency to work loose and must therefore be checked regularly and tightened if needed. Ignored, they present the possibility of collapse, with destruction of the ladder and death or injury to fire fighters.
In the field, the greatest care should be taken to see to the ladder’s stability. When placed for operation the aerial should be on as level a surface as possible. If the truck must be positioned on a grade that causes it to tip sidewise, the angle of the ladder, extension and loading must be reduced.
Loading is always a problem. The question comes up: “How many men and how much equipment should be allowed on a ladder at the same time?”
Many variables are involved in the answer to this question. Such variables include the size of the ladder, the degree of elevation, extension of the sections, and whether or not the ladder is unsupported (in cantilever) among others. And the answers can only be found in the manual relating to the particular make and model.
Generally, with the ladder in cantilever there is no need for any men to be on it. But within limitations of angle and extension there may be one man at the top and one half way up. At other times 12 men are permitted on the ladder, and on still others only three—it all depends on the design characteristics and will be stated in the operating manual.
Icing also presents a problem in loading. An accumulation of ice on a ladder can throw all calculations off and might render the ladder unusable. The added weight could be tremendous, particularly in a ladder pipe operation in bitter weather. However, icing presents its biggest problem when it comes time to bed the ladder and return to quarters.
A heavy layer of grease as mentioned above helps prevent ice accumulation that binds sections in the slides. But when this fails, other methods must be resorted to. Steam from a thawing apparatus is probably the best method of freeing a frozen ladder, but this is a long drawn-out operation. Another method is to wash down the stuck parts with water from a hose, which water is, of course, above the freezing point and might melt the ice. However this method will only work when the air temperature is only several degrees below freezing and not in real bitter weather. As a last resort the ladder is bedded, if possible, with the sections till extended and the apparatus taken back to quarters to thaw.
Some apparatus come equipped with a de-icing valve as mentioned in Part 1. Operation of such valve permits working pressure to go as high as 1,000 psi or more, and in effect bypasses the relief valve. It should be used with extreme care. Often when the sections are thought to be bound, the problem lies with frozen ladder locks. The ladder-lock control might be in the off position, but the locks themselves are still engaged because of ice. This situation can be generally relieved by having a man ascend the ladder, free the locks and tie them back with a piece of wire if they won’t remain in the off position.
Another precaution to be taken involves the use of operating levers on the pedestal. These levers actually operate a solenoid which, in turn, controls the throttle and hence the pressure in pounds per square inch that is transmitted to moving part selected. Mr. Ferris has observed a tendency by some chauffeurs to feather or baby the controls in an attempt to move the designated part more slowly. He cautions against this since it can result in burnt-out switches.
Should the accelerating solenoid become inoperative for this or any other reason, set hand throttle at 900 rpm to position ladder and when this is done, lower rpm to idle. Chauffeurs should keep a constant eye on pressure and rpm and if either exceeds 1,050 while operating, a mechanic must be called.
Safety in operations
Both the Division of Training and the Division of Repairs and Transportation call for extreme care by personnel using metal aerials. Pressures developed by the hydraulic machinery can snap a man’s arm off or crush his body with the greatest of ease.
For this reason, no one is permitted on a metal aerial while it is being raised from the bed nor while the sections are extending. Occasionally, conditions may warrant a man remaining on a ladder while it rotates, but the operator must make absolutely sure that the ladder locks are engaged. He must also disengage the power take-off and rotate the turntable by the hand crank. As mentioned before, this prevents any possible jerking motions that would endanger the man on the ladder or possibly damage the ladder itself.
Additional safety recommendations, as well as other points of operation too numerous to elaborate on in an article of this scope, can be found in the manufacturers’ manuals. Use them!