WOODEN WATER PIPES.

Pukekohe & Waiuku Times, Volume 5, Issue 150, 25 February 1916, Page 4 (Supplement)

WOODEN WATER PIPES.

The fact that wood is now being largely used in the United States a? a material for waterpipes is of interest when :t is recalled that the earliest pipes were made of wood, which wai later displaced by iron or steel. The Engineering Correspondent of the "Sheffield Daily Telegraph" has recently given a very interesting account of ancient and modern wood pipes, in which iie states that in early Colonial days, and probably for some time aftel the Declaration of Independence, the use of wood for delivering water was a necessity. The pipes of those days were crude, consisting of logs with holes roughly bored through them, the successive lengths being joined by the crudest of methods. One end of each length was roughly tapered, and was forced into the hole in the end of the next length. Notwithstanding their roughness and crudity, the old pipes d d their work for a very long time, and in some parts of America are only now being taken up. In a 1 mo»t every case the wood pipes are found to be in good condition. It is on record also that some -MX) miles of wood pipes were laid in London in the year 1613. and that when some of them were removed from Piccadilly in the year 1862 they were found to lie in good condition. In the year 1798 the well-known Aaron Burr is reported to have built a tank to supply the inhabitants of New York in those days with water though wooden pipes. Some of these pipes have been taken up in the last few years, and were found to be still in good condition.

STILL IN USE. Though iron and steel have taken their place in America in what may bo termed the pipe world, the use of wooden pipes has by no means been discontinued. They are still employed for delivering compressed air in mines, and a very much improved form of pipe is being laid down at the present day in different States for the supply of water. The crude, irregularly-bored wooden pipe very early gave place to the centrally bored log, and it is the early pipes that were made in that way that are being dug up from time to time and found still in good condition. The city of Philadelphia was supplied with water in 1799 through pipes made of oak logs about 'i feet in diameter, rough dressed on the outs de, and with bores ranging from (5 in. to 12 in. The pipes were held together by hand-made iron hands, and the bulk of the length of pipes were strengthened in the same way. Some of these pipes that were used for many decades after they were laid were found when dug up quite recently to be as sound and serviceable as the day they were hud, though the iron hands had completely rusted away. The first improvement in the manufacture of wood pipes was the application of a .steel band to the outside of the wooden pipe, and this construction still obtains for pipes up to (3 in. diameter, the steel being protected by an asphaltmil compound, which, it is claimed, penetrates into the wood. For larger sizes from Gin. up to 48 ill. the pipes are built up of staves. Pipes larger than 18 in. can he made if required, but the above ligure is the standard stock limit. The firms who have devoted then-selves to the manufacture of wooden pipes say that they have been obliged to abandon the manufacture of solid pipes of larger than 0 in. diameter because of the diminishing supply of large logs for the purpose. The American Congress has been obliged to step in to regulate the depletion of the virgin American forests. ;nd meanwhile large pipes are made in the manner described. The joint'ng of wood pipes was necessarily a troublesome affair. The early crude joints leaked, and there was no means of stopping it. The joints of the improved pipes, with central here and steel band wrapping, also leaked considerably. It s claimed, however, that the tenon or mortise joint now employed fits absolutely tight and makes a perfect joint.

THE MODFiiX TYPE. Tho Tiiniii;fac-ture of wood pipes has so greatly improved that at the present time it is claimed that pipes can lie made to withstand a pressure of 700 feet of water. The wood pipes arc found to have many advantages. The wood shell is a poor conductor of heat, and ho the chance of freezing in winter is considerably lessened. In several parts of America the temperatures during several month.s of the year arc very low indeed, .'lOdeg. E. below freezing point being quite common. It is also found that even when frost does occur, the elasticity of wood allows for the increase of volume of the water when freezing, and also that if any damage is done to the wood in the process of freezing, when thaw sets in the wood iibres close up again, and the pipe is as good as before. It will be remembered that the tiruble with iron pipes is, if the water :s allowed to freeze in them, the pipes may lie cracked, and when thaw sets in the water escapes through the crack. Wood pipes have been found of great service where water eontaim sails in solution, as often happens in mines, the salt Inning practically no effect upon the wood, while iron pipes are very quickly thinned by corrosion. In America steam is delivered over large areas for power and tor heating through pipes laid in the ground. In some cases steam is taken directly from a battery of boilers, in other cases the exhaust steam from a power station is used, and it is said that money earned by the waste product, the exhaust steam, is often greater than that earned by the station itself. Steam pipes are insulated in some parts of America by a special form of wood pipe. The construction of the pipe is s milar to that for delivering water, and it is lined with tinned iron in addition. According to tests that have been made upon the thermal insulating properties of tho protecting wooden pipes, the loss duo to heat leakage, as measured bv the steam condensed, is considerably less than that with pipes in-ulated with any other substance. The pipes, of course, occupy a larger space in the ground than iron pipes, both when cmployed for carrying water and when used to protect steam pipes. The tlrcknesses of wood pipes run into several inclit s, where steel or iron pipes would onlv run into fractions of an inch.