WAITETI RAILWAY MORKS.

Waikato Times, Volume XXX, Issue 2439, 28 February 1888, Page 3

WAITETI RAILWAY MORKS.

[by our special RKI'OKTEU.]

The work on the Waiteti section is almost completed as far as the earthworks are concerned, all the cuttings 'th the exception of one or two through rook will be done in a few weeks, the latter will take two or three months to finish. The rock is hard limestone and is blasted out with powder or dynamite. In removing stumps and roots the latter is employed. I saw six cartridges put into a tawa stump, and the only effect it had was to split it in several places, another hole was bored and eight cartridges were put in and exploded with better effect, for the stump (a bie one) was blown to pieces. As much rock as was expected was not met with on this section. the opinion of a good many was that many of the cuttings would be found to go through solid rock, which, bowever, has proved to be the exception. In one cutting which was, thought would be almost solid stone a very curious thing is to be seen, several seams--of limestone were met with on each side, but strange to sav most of them ended exactly at the proper width of the outtinc, some sloping back at the proper angle so that it was not necessary to touch them at all, othcis had only a few inches taken oil, in one ease only the scam ran across the line, and of course had to be blasted. It looks as if the engineer who laid out the line was aware of the formation of the seams, and where each ended and laid out the line accordingly, furthermore the line curre3 slightly in going through the spur which makes the case still more singular. Having stone in the cuttings is by no means a great drawback, for where such is the ease there are no slips, whieh cannot be said of all the earth cuttings in one of which—that on the south end of the viaduct—a slip of about twelve thousand yards occurred. This is due to the presence of clay, which looks like impure " hematite," but which I have been told is " limonite." This clay is of an oily or greasy nature, and when the cutting was put through, the earth overlying it slipped off. A similar accident occurred in another cutting, I believe, due to the same cause. The whole of this section consists of cutting and embankment, which renders it an expensive job. A great number of the cuttings were sub-let, but the whole of the stone cuttings were, and are being put through, by the contractors. The largest of these that I saw contained 27,000 yards, but there is, I believe, a larger one some miles down the line. In the course of a few weeks, there will be very few men employed on the line, and when the stone cuttings are finished, there will then be none left except those at the foundry works at Te Kuiti, and a few at the viaduct at Waiteti. All the boring, drilling, punching, angle iron works, and making of rivets is done at the foundry. An engine has being put in position, and the iron work is being carried on from 7 a.m. till 12.30 a.m., there being two shifts. In the machine shed are four forges, the blasts for which are supplied by a fan driven by the engine. The hammer used in making the rivets instead of being worked by steam, is worked by a treadle, the handle is attached to a frame, over wl.ich and near the roof is a spring beam from which there is a connecting rod to the hammer, by working the treadle the the spring beam is set in motion and as it rises and falls the hammer is set in motion. The rod iron for the rivets is heated almost to a white heat, a piece the required length cut and put in a socket with two or three inches according to the size of the rivet head required projecting upwards from the socket, this is beaten down by the spring hammer and so the head is formed. The socket is fixed on a large block of iron about two feet high. Projecting laterally from this latter and near the ground is an iron beam which runs into the. centre of the block, from the inner end of this beam a rod of steel runs up perpendicularly into the socket which holds the rivet, when the head is finished the projecting end of the iron beam is struck without depressing the'outer end. This raises the other end forcing the steel rod upwards and so the rivet is shot out of the socket without handling. Water is frequently poured over the socket to prevent its temper being spoiled by the continuous heat. There are two men employed at this work turning out about four hundred rivets a day. The drilling is done with what is known as twist drills and while boring they are kept continually wet with a mixture of soft soap and water. A noticablc feature in the machinery is a circular " cold " saw for cutting iron. This saw which is two feet in diameter revolves very slowly the speed being only six revolutions a minute. The iron to be cut is fixed immovably in a frame for the purpose, while the bed in which the saw is fixed moves forward very slowly. The teeth are very small, apparently about the size of those of a carpenter's rip saw, but the saw itself is about three times the thickness of a rip saw. Messrs J. and A. Anderson are the only firm in the colony who u.-o the " cold''saw. They have two besides the one at Kuiti—one at Lyt.tleton and one lit Christcbureh. Tho advantages of a "cold" saw are: the iron to be out does not require beating', and the face of the cut does not require any dressing afterwards, as the saw leaves it quite smooth. It is fixed over a trougli, which contains a solution of soft soap and water, which keeps it moist continually. Thero is al<o an eight-drill boring machine, but it will not be worked, I believe, partly on account of the extra power required, and also because a concrete bed would have to be laid down for it; the single drills (two) are therefore used. The wholo of the motive power is supplied from an eighthorse power engine. All the work in connection with the viaduct will take about a year to finish. The total length of the structure is 115 ft.; greatest heiuht in the centre from the bed of tho creek, 115 ft. There are three concrete piers as a foundation for tho supports, one on each side and one in the centre of the gorge. Two are now finished, while that at the south side is well on, and will soon be completed. Each pier Tests upon a solid rock formation. The following is an instance of the peculiar formation of the ground :—ln one part of tho south pier the rock came up to the surface, and just in front of this rock at one corner the men had to sink 27ft. to get tho foundation ; at another place they had to sink a little over 20, and at another less than 20ft. These varying depths were all found within an area of less than 30 feet. Besides the three piers, there will be an abutment at each end of the viaduct which will be built up from a position perhaps twenty or thirty feet below the level of the line, these tilso will rest upon a rock foundation. ' Here also is another instance of the good fortune which was experienced in the cutting referred to above, on looking for a foundation for the northern abutment it was found that if the line had been laid out a couple of feet to one side, (the west), the foundation would have only rested partly on rock, as it is the rock comes exactly as far as is required for the base and no farther. In quarrying for one of the piers some hydraulic limestone was found which was sent to Wellington to be tested. The reply was that it yielded hydraulic lime, should it prove to be of good quality there is an unlimited supply to be had here. Mr Hursthouse sent some samples of the stone lying on the surface to Wellington for analysis, and the returns were from ninety-three to ninety-six per cent, pure carbonate of lime. This is good news for Waikato farmers, and does awav with the idea that the was dolomite, very refactory and containing only thirty per cent, of lime. This idea originated in the fact that hearths built of the stone were not affected by the heat. Subsequent experiments however, showed that if subjected to considerable heat it burned very well. I put a piece in the firo box of the engine at the foundry, but as it was in only about six hours it was not burned through, but I

'nave in my possession a small quantity of lime taken off the surface, which I shall lie pleased to show to anyone who desires to see it. In conclusion, I beg to express my tlmnks to Mr Robertson, manager, Mr Alabaster, engineer, and Mr Moss, receiving clerk at To Kuiti, for their courtesy in showing me the works, explaining matters and supplying me with the information contained in this letter.