flagpole FLAGPOLE (by David Lawyer, 1993) Steel flagpole set in concrete by the Boy Scout troop 28 (Throop's) under direction of Benjamin Robinson. A gift of Mr. Mel Wood. Dedicated Feb. 16, 1930. Height (top of base to pulley) slightly (a few inches) over 45 feet. Based on the 10% rule, it may extend about 4 1/2 feet underground where it's likely set in concrete. Used braided polyester rope (1993) as a halyard (naturally sunlight resistant) size 5/16". Bought it (1993) in San Pedro at a ship supply warehouse for less that half the price that flagpole companies charge for it. The flagpole is telescopic in construction consisting of 5 different diameters of steel pipe: 5", 4.5", 4", 3.5", ?". They actually measure (by taping circumference and dividing by pi) 5.05, 4.54, 4.04, 3.54, ?. Thus the paint layers account for about .02" on the surface of the pipe (=> .04" for dia.). It turns out that 4 1/2" water pipe has an diameter of exactly 5" and an od of 4.506" which would allow the 4.5" pipe to telescope into it. Similarly for other sizes of water pipe 3" to 4 1/2". But 2 1/2" standard pipe has an od of only 2.875" which is what the first ? above may be (not yet measured). The section modulus is about 1 cubic inch (per Machinery's Handbook) so that a person weighing 200 lb. and with center of mass located one ft. to the side of the pole, would create 2400 inch-pounds of moment on the small 2 1/2" pipe, resulting in about 2,400 psi stress on the extreme fiber. The pipe might have a yield point of 15,000 psi resulting in a safety factor of 6. But don't lean too far to the side when climbing the top (thinnest) section of pole. The top pulley rotates on what is called a "cap truck". The pulley bearing has about 1/16 " play. A replacement cap truck (including pulley) costs about $50 in 1993. Top of pole has a reducer pipe fitting which has a 3/4" pipe coming out the top. The truck is on the 3/4" pipe likely attached on standard pipe threads. Lubed Mar. 1994. To climb the flagpole use a tall ladder and lash it tightly to the pole with straps so that rungs of ladder cannot slip from side to side. For an extension ladder, lay it flat on ground with feet against concrete base. Then erect ladder (not extended) and lift feet onto base, hold it against pole and lash it to pole about 6 ft. off ground. Then climb it, holding on to pole to prevent ladder from moving. Lash it again near top. Then return to the ground and pull on rope to extend ladder all the way up. Then climb up extension part and lash it in a couple of places (including the top of the ladder). If the ladder doesn't reach, the top (a 40 ft. ladder only extends to 35-36 ft. & will not quite reach) use prussik slings (1/4" or larger mountaineering rope or 1" webbing will do) to climb up to the top of the pole. Once a girth hitch around the pole worked 0K but after the pole was sanded smooth a prussik knot was required. Also, use a chest harness looped around pole for safety (and to permit working with both hands). A website on flagpoles mentions the obvious: Don't try to use the halyard rope (the one with the flag on it) to climb the pole (unless you know there is a big safety factor). To paint the pole, start from the top and work down. When you reach (with the paint) the top of the ladder, descend and lower the ladder about 6 ft. Then paint the 6 ft. section thus exposed above the top of the ladder. In this way, the rungs of the ladder don't interfere with the painting. Carry a quart paint can strapped tightly to your tool belt (or the like) so that you don't need to hold a paint can. Take care not to bounce or jump, otherwise paint may splash out. One could also use prussiking all the way from the ground and avoid the use of a ladder but it's awkward due to having to push up such large diameter prussiks. Bear in mind that the prussik slings will become longer as you go up the pole due the decreasing diameter of the pole. One might compensate for this by having two foot loops on each prussik sling. This is similar to a short webbing ladder or etrier. In 1993 a flagpole Co. quoted $200 as the fee for climbing the pole and installing the rope and $300 for painting it. So doing it yourself saves $'s. It took about 7 hrs. to paint it (and lube turret) so each hr. of work saved $43 in 1993. In 1992 the flagpole was inspected inside using a flashlight to look thru cleat holes at night. Inside, it looks like silver colored paint (not galvanized). Some small bright orange spots are visible inside. They are not rust, and are a mystery. Many other steel flagpoles of this age have rusted out from the inside but this was well made. It doesn't seem to have any leaks as it will hold air pressure. In 1993 pulled sideways in various directions with about 50 lb. on rope attached near top. Pole did not get bent or crack => it is fairly strong. The original cleat holes (1/4-20 thread size) are on 1 9/32 in. centers. After an unsuccessful search for such a cleat, I bought one at Berg Hardware with 1 3/8 in. centers (1 12/32). Then the holes in the cleat were enlarged by drilling sideways with a 1/4 in. twist drill bit. Flag sizes are (in ft.): 8x12, 6x10, 5x8, 4x6, 3x5. Some come roped with entire length of rope while others have only eyelets. Hortie-Van of Pasadena carries them. Flag companies suggest a 6x10 if only one flag is to be flown. A chart on the Internet says 8x12. The Earth Flag seems to come in only 3x5 (too small for us). In 1993 a 5x8 US nylon flag was obtained for about $20 from our local Congressman was flown. Other sources wanted 3 times this price.