GB2162951A - Wind and tide monitor - Google Patents

Abstract

A high wind monitor comprises a heavy elongate member or monolith (1) mounted to a base (18) so that the monolith is substantially vertical and is free to move under the effect of high wind pressure in any azimuthal direction. Indicators or sensors are provided around the base to sense the movement of the monolith to give a record or warning of wind force on the monolith. The monitor is particularly suitable for high wind conditions as may be present in hurricanes, typhoons and cyclones. The apparatus may be modified to sense tidal surges. <IMAGE>

Description

SPECIFICATION Hurricane monitor The present invention relates to monitors for very high winds such as are present -in hurricanes,-typhoons, cyclones and the like.

Normally winds are monitored by cup type rotating anemometers. Such anemometers are suitable for light winds and even up to winds of Beaufort Scale 1 0. However, when higher wind speeds are present the tendency is for this type of monitor to fail due to lack of robustness.

Simple plate type wind gauges as have also been used are unsuitable for. hurricanes, ty phoons and the like due to the frequently rapid change of wind force and direction.

A high wind monitor according to the pre sent invention comprises a heavy elongate member mounted to a base so that its. elon gate axis is substantially vertical, the mount ing being such that the bottom of the member is substantially fixed: in azimuth whilst the top of the member is free to move under the effect of high wind pressure in any azimuthal direction and wherein the movement of the member is arranged to be sensed.

The weight of the elongate member herein after referred to in no restrictive sense as the 'monolith' (that is to say it may be more than one part), prevents fluctuation in light winds.

Preferably to assist in stability the 'monolith' should have its lower half of greater mass than its- upper half, that is the weight should be concentrated at or towards the bottom of the 'monolith'.

Preferably to increase stability the 'monol ith' should be resiliently mounted to the base, and in a preferred embodiment this should comprise three or more resilient units evenly spaced around the base acting between the 'monolith' bottom and the base so that the 'monolith' can rock under lateral pressure.

In order to record wind force a suitable mechanical or electrical indicator can be pro vided in the base actuated by each one of the resilient units. Such indicators can be a stylus arranged to mark a rotatable drum, the drum being rotated by a ratchet actuated by the 'monolith' movement. Alternatively the drum may be rotated electrically. The recorder may also be a strain gauge operated device.

The 'monolith' is preferably substantially circular in cross section and substantially po inted at its upper extremity. Such shaping of the 'monolith' may also provide an aestheti cally pleasing shape. The 'monolith' construc tion is also highly resistant to vandalism.

The top surface of the base or bottom surface of the 'monolith' or both are prefera bly convex to assist pivotal action of the 'monolith' on the base.

An embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is an elevation of a monitor according to the invention, Figure 2 is cross-sectional top view of the base of the monitor of Fig. 1, Figure 3 is a cross-sectional detail of part of the base and part of the bottom of the 'monolith' of the monitor of Fig. 1 showing mounting, and Figure 4 is a plan view of the one resilient mounting means of the monitor taken at approximately A-A in Fig. 3.

The monitor comprises a monolith 1 about 6 metres-high of approximately circular crosssection having a maximum diameter at point 2 of about 1.3 metres narrowing upwardly to a substantially pointed extremity 3 and slightly narrowing towards its bottom 4 to a convex bottom surface to approximately 1.2 metres in diameter at point 8.

The 'monolith' is suitably moulded from concrete with suitable internal reinforcement and may be provided with decorative. shallow fluting 1 0. The shape of the 'monolith' may however take other forms.

The bottom of the 'monolith' is provided with a dished cast iron or cast steel bearing plate 1 2 to which are fixed steel reinforcing bars 1 4 forming the internal reinforcement.

Alternatively high tensile steel anchor bars may be fixed to the plate 8 at one point and then to the main internal reinforcement of mild steel at another point or points.

The plate 8 may be coated to resist corrosion.

The 'monolith' 1 seats on a bearing plate 1 6 of the base 1 8. Bearing plate 16 is convexly dished to a similar radius as bearing plate 1 2 so that the contact area between the bearing plates is small in relation to the diameter at 8. The radius of dishing of both plates is large so that the maximum gap at 20 is about 75 mm. The base bearing plate 1 6 may be lipped upwardly as at 22 to prevent extraneous blown matter from lodging in gap 20 and to retain viscous sealant and lipped downwardly as at 24 to seat on a circular segmented bearing case iron ring 26.The cross section of ring 26 is of a 'I' form so as to provide a lower bearing surface on the concrete base 1 8 and to provide an upper bearing surface coated with a sealant such as bitumin to carry plate 16.

At 120 intervals resilient units 30 are provided which comprise a coiled compression spring 32 acting between a chamber wall 34 of chamber 35 and a yoke 36 attached to rod 38. Yoke 36 has a pair of dampers 40 also attached to wall 34. The spring pressure may be adjusted by means of a nut 42 on rod 38, the correct setting being by means of a torsion spanner nut 42. Rod 38 in each case is fixed through a gland in wall 34 to link or bell crank 44 pivotted on bracket 28 fixed to ring 26. The glands exclude sealant filling pockets 1 7 containing cranks 44 from the chambers 35 of units 30. From link 44 extends a high tensile steel rod or anchor bar 46 which is anchored firmly in the 'monolith' 1.The chambers 35 also enclose recording devices of a suitable type which may be entirely mechanical of a known type actuated by movement of yokes 38 or partly or wholly electrically operated. The readings from each of the three recorders can be compared visually or electronically to give wind direction and force depending on the tilt of the 'monol ith'. Suitable lockable cast iron inspection covers 48 conforming to the drainage slope of the base may be provided for access to the chambers 35. The chambers- 35 have further screwed down covers 49.

The foundation for base 1 8 requires to be very firm and in many cases it will be necessary to- provide piles 50.

Further regarding the recorders these may be in the case of a remote location a stylus -attached to each yoke in scratching contact with a smoked glass plate which can be removed after each hurricane for transcription of the mark. In a more sophisticated arrangement the plate can be in the form of a glass drum smoked to record the stylus movement and driven by clockwork or by a dry cell operated solenoid or a ratchet drive from the yoke 36 Recorders can also be electrical and linked by cable or radio to a meterological station. Preferably the link is by underground cable to a nearby station which avoids problems in radio transmission during hurricanes.

The weight of the 'monolith', the initial compression of the coil springs the shock absorbers and the viscidity of the sealing between plate 1 6 and ring 26 all contribute to making the monitor poorly responsive to casual shock, impact or gusting, so that only sustained and high wind pressure will cause the recorders to operate.

Whilst the monitor may well be a feature of visual and even aesthetic interest, the design is not be offensive visually and the construction is resistant to vandalism.

The monitor described is primarily a wind monitor, but the construction is such that it acts to record high lateral fluid forces of whatever nature, such as abnormal tidal surges when the monitor is subject to tidal flooding when positiond on a low coast line.

Claims (11)

1. A high wind monitor comprising a heavy elongate member mounted to a base so that its elongate axis is substantially vertical, the mounting being such that the bottom of the member is substantially fixed in azimuth whilst the top of the member is free to move under the effect of high wind pressure in any azimuthal direction and including sensing means for sensing the movement of the mem ber.

2. A monitor according to Claim 1 wherein the lower half of the elongate member has a greater mass than its upper half.

3. A monitor according to Claim 1 or 2 wherein the elongate member is-resiliently mounted to the base.

4. A monitor according to Claim 3 wherein the resilient mounting comprises three or more resilient units evenly spaced around the base acting between the bottom of the member and the base so that the member can rock under lateral pressure.

5. A monitor according to Claim 4 wherein at least three of the resilient units each actuate a wind sensing indicator.

6. A monitor according to Claim 5 wherein the indicators are arranged to mark a rotatable drum.

7. A monitor as claimed in Claim 5 wherein the indicator is a strain gauge operated device.

8. A monitor as claimed in any one of Claims 1 to 7 wherein the cross section of the elongate member is substantially circular and the member is pointed at its upper extremity.

9. A monitor as claimed in any one of Claims 1 to 8 wherein the bottom surface of the elongate member is convex.

10. A monitor as claimed in any one of Claims 1 to 9 wherein the base is convex.

11. A monitor according to any one of Claims 1 to 10 wherein the elongate member is about 6 metres high.

1 2. A high -wind monitor substantially as described with reference to Figs. 1 to 3 of the accompanying drawings.