NEW WELLAND CANAL

Wanganui Chronicle, Volume LXXXII, Issue 19478, 24 December 1925, Page 5

NEW WELLAND CANAL

GEE AT NGINEEBING TEAT. PANAMA SURPASSED. The last contract has been let for the completion of the now Welland Canal connecting Lake Erie with Lake Ontario, forming the first lijik in the scheme of navigation which will enable ocean liners, instead of halting at Montreal, to steam westward to the far inland ports of Duluth and Port Arthur and nil intervening points. Without much flourish or advertisement work on the new Welland Canal has been proceeding for 13 years. It will be completed according to present estimates in five years more. Delay has been due to the war. All the world sings the praises of the Panama Canal, but from an engineering point of view, the new Weiland Canal is a mightier feat. While it is only 25 miles long as compared with Panama’s 50, Panama’s summit is only 85ft above its entrances, while the Welland must overcome a lift of 326 ft, which owing to the Falls of Niagara and accompanying rapids, separates the higher level of Lake Eric from Lake Ontario. As a consequence, lifting apparatus is on a colossal ®calo. To give some idea of the magnitude of tin* work, it may be noted that if all the earth ami rock to be excavated were loaded on dump ears, the train would stretch for 15,000 miies, the length of the great wall of China. The amount of concrete to be used would be sufficient to build a. solid concrete wall 20ft high, 6ft wide, and 100 miles long. Fourth Reconstruction.

A hundred years ago the first Welland Canal was built connecting the present terminus, Port Colborne on Lake Erie, with Port Dalhousie on Lake Ontario. Three times the work has been reconstructed and the existing canal accommodates a substantial share of lake navigation. But the new enterprise is infinitely more ambitious. The northern or Lake Ontario teri minus has been moved from Port Dalhousie, three or four miles east, to Port Weller (named after the engineer). The canal will follow an almost straight line and will be five miles shorter than the old. There will be onlv seven locks on the. new. as compared with 27 on the old. Not only the largest steamers on the Great Lakes can come thr. ugh the locks, but come through in one-third the time. Instead of 24 hours for passage through the present structure, it is estimated that only eight hours will be required for the new. Another way to estimate the immensity of this undertaking, calculated to cost £10.000,000 even at 1912 prices, is tc- say that while the present canal will accommodate only boats at the most 360 ft iu length, the new one can let through vessels measuring 800 ft., 200 ft. more than the largest boat now plying on the lakes. Locks 800 ft. Long. Some of the new locks are among the largest in thv world. The locks or j the present canal tiro only 250 ft. long. 45ft. wide and 14ft in depth. The new arc not only 800 ft long, but 80ft I wide, with 30ft, of water over the gate I sills at extremely low stages of the lake. Capacity loads for vessels during ' the present low water levels in the old canal are 71,000 bushels. Not only will the Great Morden, with her 5U0,000 bushel , and 22ft draught pass through the new locks, but have Bft to spare. It will take just exactly eight minutes to clear this gigantic freighter through each lift. These huge lock compartments, built throughout of concrete and founded on bed-rock, will have walls towering 82ft above the gate sills. Two of the locks will have ■walls over 100 ft high. The gates, a notable feature, are to be among - the largest iu tiie world, weighing 1100 tons each. Three of them arc twin locks in flight siimlar to the Gatun I locks of the Panama Canal, that is, each I pair rising one abovj the other. Some Special Features. The engineering world has its attention attracted to some of the special features of tiie work. The pair of twin guartl gates located immediately to the south of lock No. 7 are outstanding. This is a special protection against the | heavy body of water formed by Lake Erie. Another new device is a pond at the head of each lift lock, acting as a regulating basin from which the water to fill the locks will be drawn instead of from the canal.

These huge reservoirs, now well under construction, varying in area from 107 to 150 acres, are to prevent the formation of objectionable currents and surges in the locks and canal. Since the ship canal is to be carried over the Welland River, another engineering feat is required here to raise the level of the.river to that of the summit level of the canal. This is to be done by a dam across the river. For construction purposes the work of the canal was divided into nine sections, No- 1 being at the Lake Ontario end of the.canal, and No 9 at the Lake Erie or Port Colborne end. The first three sections include the Lake Ontario entrance and all the seven lift locks, each one of which will raise or lower a vessel These sections, begun in 1912, will all be ready for navigation in three years. Section No 5, between Thorold and Port Colborne, really an enlargement of the present canal, is the only section completed and in use. Section four, south of Thorold, is almost finished. The contract for section 6 has just been awarded. Great Harbour Works.

The huge harbour- breakwaters at both Port Weller and Port Colborne are a fascinating sight as they take shape. At Port Weller the entrance piers are placed about a mile from shore, where the water is 30ft deep. A wide channel is being dredged from these piers to the first lock and reinforced by concrete walls, along which vessels may lie. From the shore-line of the lake to the outer entrance piers a huge embankment is being constructed, 500 ft. in width, on each side of the channel, composed of material ex* eavated from the canal. Avt Port Colborne the new breakwater will be half a-mile long, and 500 ft iu width, and will protect the harbour and canal from the heavy winds. Full use of the new canal will have to wait for a similar development on the Ht. Lawrence. Only then will the Great Lakes be able to realise their dream of real ocean navigation.