By Dirigible to the North Pole

Hawke's Bay Tribune, Volume XIII, Issue 285, 17 November 1923, Page 9

By Dirigible to the North Pole

American Airmen to make 6000 Mile Trip

Flight to be made when Weather Conditions Favourable

The most daring and romantic long-distant flight in the history of aviation has been planned by 1 the Naval Air Service of the United States. A giant airship, the largest ever designed, is to be built at Lakehurst, New Jersey, for a trip across the North Pole next summer. From 20 to 25 picked men will form the crew, and the whole expedition, it is expected, will be accomplished in seven days. About 6000 miles will be covered. "PREPARATIONS are now nearing completion at the Air Service Station at New Jersey for the daring attempt to navigate a dirigible airship across the North Pole. The craft that has been selected for the hazardous trip is the airship Z.R.1., now in course of construction. It will be the largest dirigible in existence, and will he inflated, for the North Pole adventure, with helium, thus minimising the danger of fire in the air. The flight is to be made next summer, when weather conditions around the Pole are likely to be better than at any other time of the year. The start will, it is expected, be made from the hangars at Lakehurst, but it has not yet been determined what route will be followed. Of the two possible ways one would lead the airship over water and Ice entirely, and the other part of the way over land. Both lead out of New York, follow closely together towards Greenland and past Cape Columbia, the fathest north base of Peary, and on to the Pole. 3000 Miles Each Way The distance by sea to the Pole is approximately 3600 miles, although by air it may be somewhat shorter, since

an airship would be able to cut clean across places that would involve a detour for a ship. It will be a tremendous adventure into- the unknown, sinc'v very little knowledge is possessed of the air currents that would be encountered. If it is successfully accomplished—and Admiral William Moffett, tho head of the Bureau of Aeronautics, of the United States Navy Department, is convinced that it can be done—then. it will be the greatest feat in the history of lighter-than-air craft, and it will also he the longest non-stop flight ever made by airship. A crew of from 20 to 25 will be carried. and great rivalry is being shown for the honour of taking part in this attempt to conquer the Pole by air.

No Especial Danger. It is contended by those responsible for the project that there is no greater risk in the venture than there would be in any flight Uveir extensive stretches of ocean or across uncharted country. The primary intention is not that of a Polar expedition, but the trip is to he regarded as an aid to the strong development of airships in the American Navy. It will demonstrate the behaviour of lighter-than-air-craft in the worst possible weather, and will provide excellent training ifi navigation. ]f it should be found that during the whole or part of the year atmospheric conditions do not make flying hazardous, theire it is intended to take stops to establish Polar airways that will link up England, Japan, Alaska, and Siberia, thus reducing to a minimum the timo that will bo occupied in travelling to and from these places.

Preliminary soundings that have | been carried out as near to the 1 North Pole as has been practicable reveal that the upper air is i not nearly so cold as is popularly ; believed, except during the winter. • It is only near the surface of the earth, where the water has been reduce-1 to exceptionally low temperature, that 50 or 60 degrees of frost have to he endured. I In the long Polar summer the temperatures in the altitudes at. which airships would fly. appear to be little below those registered in a normal winter in England. It is only during the winter six months that conditions would render aidship trips an impossibility. ' The Z.R.I. which has been chosen for tho daring venture, will be equipped with six engines, each developing 300 h.p. Each motor will he fitted into a separate gondola, so that the loss of the power of two or even three units will have little difference on the navigability and the manoeuvrability of tho vessel. Fuel, in all 5450 gallons, is to be stored in over 60 different fuel tanks. These will be fitted in a long corridor running from stem to stern of the ship. In case of emergency, requiring the dropping’of ballast to keep the vessel at a safe flying height, 16 of these j tanks will be detachable and thrown • overboard. 1 I From nose* to tail the is 680 ft. > ' long. Powerful radio instruments are , ;to be installed, and it is hoped that i by this means it will be possible to i keep in touch with the nearest land ; station throughout the whole flight. ■ ; On the very top of the ship a control tower is being placed for making i 1 weather and other observations. ■I It is computed that the whole ■ I trip will occupy less than seven days, which will make it the most . rapid Polar exploration in history, ’ ; but supplies will be carried that | will suffice for a stay of between a ' j fortnight and three weeks in the 1 ’ air. * I If the voyage to the North Pole is successfully accomplished, it is intendl ed to send the Z.R.L on a trip round the world.

FLOOD DANGER IN HAWKE’S BAY. (Continued from Second Column). FURTHER REDUCTION OF GRADIENT. It would appear that a still further reduction of the gradient is not out of the question, for reference to the same table shows that on a fall of 4 feet and a depth of 30 feet a mean velocity of 12 feet per second may be looked for, yielding a discharge of 116.(MM) cusecs- Even at one-third of that depth the estimated mean velocity is 61 feet per second. A velocity still sufficient to move the finer portion of the bed load. From which it will }>e seen that in a property trained river every freshet will “get a move on.” In Table 111, the value of “n” has been taken as .0275. All this doubtless sounds very remarkable and I expect you are inclined to be sceptical, but you will find it to be true. And it is wholly accounted for by the vast extent and rough condition of the river beds. I have said that depth is more important than fall. If you will look at J able IV. you will see the compartive effects of increasing the fall and of increasing the depth. TABLE IV. Showing that the depth of a river is more important than its rate of fall per mile in determining its velocity. figures in the first line indicate “fall in feet per mile,” when employed with reference to the second line. They stand for “mean depth, in feet,” with reference to the third line. 1’ igures in second and third lines show the corresponding “mean velocities ,in feet per second.”

With a fall of 10ft, per mile and a depth of 10 feet you will sec that the velocity is 10.4 feet per second, jf the fall he increased to 25 feet per mile, the depth remaining the same, the velocity will he 16.5 feet per second, but if the fall of 10 feet per mile be retained and the depth be increased to 25 feet the velocity increases to 17.7 feet per second. Any of you can put these statements to a rodgh practical test. I did so on the Rangitata last Christmas and found that the flow of the stream running northwards parallel with, and just inside, the sea beach, was. at the time I gauged it ,about 10 per cent more rapid than the flow at Arundel bridge, where the fall was probably twenty times as great. These torrents make a great fuss, but they “don’t get there.” EFFECT OF LATERAL CONTRACTION. Our shingle rivers in their mountain courses afford us opportunities of studying the effect of lateral contraction/1 would instance the Mohaka river where it is crossed by the new NapierWairoa. road; and tnc Ituamahanga in the Wairarapa, immediately above the Te White bridge, where the clean swept condition of their beds justifies sanguine expectations of the benefits to be gained by artificial works of contraction elsewhere. Both these rivers, though they have a mean -width of no more than 200 feet at the points mentioned, probably cany as great floods as tho Waimakariri itself, which river itself, where it issues at its lower Gorge, is only 300 feet wide. And the Waitaki, where is leaves the hills a mile or two above Hakateramca cannot be more. The Ngaruroro in Hawke’s Bay is carrying plenty of 3in. stones throughout a reach of 3} miles above the bridge at Pakowhal, the average fall being 6| feet per mile and the depth about 15 feet. An artificial channel 300 feet wlo* in the bed with curves of large radius would probably carry the same weight of metal on a fall of 4 feet per mile with little or no increase in depth. Coming nearer home The condition of the Waimakariri at Count’s bridge is decidedly encouraging. EVIDENCE FROM NATURE. For a further piece of evidence from Nature I refer you to Kutter’s work on the * ‘Flow of Water in Rivers and other Channels,” page 213, of Hering and Trantwine’s translation which shows that the Elbe at Tetschen in Bohemia was, at the time it was gauged, carrying ‘‘coarse gravel, with pebbles up to egg size” on a fall of 2.6 feet per mile. Its mean depth being about 19 feet and the mean velocity of its flow 8 feet per second. If no serious fault can bo found with the reasoning or with the calculations supporting it, I now claim to have drawn attention to the essential principle which must govern the main design of all works for the training and control of our shingle bearing rivers. They must no longer be permitted to dissipate their energy by “spreading themselves out too thin.” Where it is necessary, as in the case of tho lower course of the Waimakariri, to flatten the gradient to a minumum, our purpose must be achieved by a concentration of the waters and by the reduction of resistance to stream flow to the least possible, so that, by these means, the pace of the river may be brought to a maximum, to the end that it may thus be enabled for all time to bear its heavy burden to the sea, and still maintain its course in a condition to carry the greatest conceivable run-off from its hydro graphic basin. This completes tho argument in favour of the principle. Wo will now consider how the principle is to be applied. PRINCIPLE PUT INTO PRACTICE. The works to put the principle into practice will have lor their object the regrading of the river bed, or rather a narrow band of it, and the excavation is to l»e done, as far as possible, by tho river itself. The river will bo enabled to do this by holding it up to its job by means of suitable training works constructed in tho river bed.

By holding the flow of the liver, or an ini[K)rtant part of it, on a predetermined course of easy and regular curvature, from which all obstructions have been removed, and upon which some surface grading has been done, a channel will in time be formed. And it will be formed partly by the erosion of the bed and partly by the accumula. tion of sand and shingle in its marginal training works of willow. In the case of the Waimakariri these works will have to be supplemented by such shortening of the lower course as calculation may prove to be advantageous. AFFORESTATION OF BANKS. As the regrading of a portion of the river-bed to form this new path for th© river will obviously be a matter of somo years, as it must be done gradually if it is to be done economically, it will b e necessary to secure the position for the time being bv means of embankments. aided by som© shortening of the course at its seaward end. The district having by this means been secured against floods, file whole area within the embankments, excepting. of course, the path of the now river, should bo afforested as opportuntiy offers. Thus while the permanent improvement works are steadily but surely making their influence felt the forest will be hindering the flow of water and claiming from it its burden. So that, while the river is cutting down its new path it will, through the agency of the forest, be building up the rest of the old bed. As the forest will offer considerable obstruction to the flow of the water, allowance must be made for this in determining the height of the embankments. While the level of the bed will be largely determined by the height of the banks, it is the level of the bed which must ultimately determine the height of the banks. And it is the river itself, operating under such conditions as may lie imposed upon it. which will determine what its bed level is to bp. The l»e<l level being thus fixed, tho height t<» which we may choose to raise the lianks will determine the possible depth. What wp may term the “gaugiugpoiut” will, of course, be the mean effective level of the sea at the river’s mouth under storm conditions, CONFORMITY WITH NATURE’S REQUIREMENTS. It must be realised that works for the control of such a force as the Wainiakariri in high flood are not to be undertaken lightly. Disaster may easily bp the consequence of lack of skill or want of good judgment-. If we would control nature we must see that our works conform to nature’s requirements. ADVANTAGES OF CONTROLLED RIVERS. Apart from their main purpose of putting the rivers under control, and so securing life and property, these works should effect some reduction, of maintenance charges, for when flowing in a channel of regular and easy curvature the banks will not be subject to surprise attacks. The points of attack will be few and will h e known be* forehand, and be protected accordingly They will occur only where the stream, owing to reversal of the curvature, crosses from one bank to the other, and they will occur nowhere else* We have yet to ascertain what timber or other growth will best serve our purpose, but the poplar is a tree likely to thrive, and to have in 30 or 40 years’ time a value for box making, sufficient to refund the whole cost of the work, with compound interest added. In addition, the forest would smother the gorse, and would bring much worthless river-bed into a more or less fertile condition, A piece of advice constantly given . by those reporting on our shingle rivers is. “Keep the river bed free from growth.” It is quite impracticable under present conditions, but the contracted waterways we are now contemplating would be swept from bank to bank by every fresh. The Rakaia railway bridge is 6000 feet long. If that river was trained the bridge could be shortened to no more than 600 feet. The replacement of timber bridges and th© construction of new ones, on new sites, will be much simplified and cheapened if the training of our rivers on th© lines indicated is generally taken in hand. CONTROL WHOLLY ESSENTIAL. Finally, I should like to do justice to a far sighted writer in the Christchurch “Press” by quoting some extracts from the leading article in the issue of February 10. 1868 an article written a few days after the great flood of that year :— “It ig now a great many years ago —almost as long ago as the commencement of the settlement—-that a Droposal was first made, which has been over and over again urged upon the public in the columns of this journal for controlling the eccentricities of great rivers. That plan was to plant the banks with willows. Had this been done twelve or fourteen years ago. the country would now be safe, and an almost incredible amount of property, as well as many lives, would have been saved. “The rivers now overflow much more readily in consequence of their beds having been gradually raised by* the deposit of debris from the hills. “Th© work must be done at lasF. The rivers must be restrained from ravaging the country. How is this to be done? The great maxim in dealing with water is this—that the water should lie made to do the work itself. You have a gigantic power, far beyond human control if yon oppose it Make it your servant and slave, and tho dreaded power becomes its own master. “These willow beds should be planted along both sides of every river. In after times these plantations would become themselves of very great value. “It is of little use making calculations as to cost in a work of this kind. “There is no doubt that it is the cheapest thing which can be done; so that ought to settle the question.’*

10 15 20 25 Fall . 10.4 12.8 14.8 16.5 Depth 10.4 13.2 15.6 17.7