Ground Ladders

[chrissoda7800]

I know NFPA 1931 deals with ground ladders, but can anyone tell me what type of rope they require for the halyard?

[rfdlou]

Duo Safety Ladder uses 3/8" manila rope
http://www.duosafety.com/parts.html

[chrissoda7800]

We used to have manila rope for the halyard, but it was replaced with a nylon rope. I just can't see the nylon rope being effective, it loses strenght when it's wet, it becomes slippery, and it will break down when exposed to heat. Is there an NFPA requirement for the type of rope to be used for fire department ground ladders?

[BKDRAFT]

Use what the manufacturer reccommends. If it is a Duo-safety ladder it would be 3/8" manila rope.

[DrewOnFire]

I know NFPA 1931 deals with ground ladders, but can anyone tell me what type of rope they require for the halyard?

NFPA 1931 4.4.5.4; "The halyard shall not be less than 9.5mm (3/8 in.) in diameter and shall have a minimum breaking strength of 374kg (825 lb). Splices shall not be permitted."

There is no mention of material used for the halyard. Would recommend following manufacturer's recommendation, as not to void any warranty.

[Rescue101]

Either rope will degrade when exposed to heat.Where are you getting your information that nylon loses it's strength when wet? It doesn't.Depending on mfg and date of mfg a ground ladder might use manila,nylon or polypropylene halyards.As the others indicated, consult your mfg for the proper type based on YOUR ladders. T.C.

[onebugle]

I know NFPA 1931 deals with ground ladders, but can anyone tell me what type of rope they require for the halyard?

The standard does not specify what type of rope to use for a halyard. The only specifications for a halyard are 1) not less than 3/8" in diameter, 2) minimum breaking stregnth 825 lbs., 3) no splices.

[kuh shise]

I had to go back and check my sources. Our fire company regularly changes the rope on newly purchased ladders from the manufacturer supplied manila to Dacron, but I didn't remember why we choose that type of line.

This source, http://nhseacadet.mainstream.net/marlinspike_training , will be of interest to those considering replacing ladder halyards.

When we investigated the suitability of nylon, dacron, polypropelene, and manila; several factors were considered. First is the strength of the line. Second, the probable deterioration of the fibers. Third, the grip provided when wearing FF gloves Last, the stretch of the line if it becomes the holding force in the unlikely event that the dogs fail in use.

Manila was poor on long term strength due to constant wetting and drying causing the fibers to become brittle or to rot.

Nylon was passed over due to stretch and grip with gloves. Although it is the strongest at 2.5 times manila for equal diameters. also 25% loss of strength when wet.

Polypropelene is very reactive to ultraviolet light and deteriorates quite quickly when exposed to sunlight. It also is relatively weak when compared with Nylon, at 1.4 times the strength of manila.

This left dacron as the rope of choice, but it wants to run through gloves (slippery) quite readily. We settled on 5/8" - eight (8) stranded marine halyard line. This weave allows for weaving back into the line when attaching around a thimble or rung. It also provides the "bumps" necessary to allow a very good grip on the line when hoisting. Ladder manufacturers usually design their pulleys for 1/2 inch manila, but most will accept the 5/8" dacron without causing undue chafing or hang-ups.

See the referenced article for estimating breaking strength of manila and its comparison to the other three prominent fibers. I would rather depend upon a 3500 lb breaking strength dacron than a 1400 lb breaking strength manila line.

Kuh Shise