Heels 1976

A Study of Leatherwood-Tramper Interaction

A Study of Leatherwood-Tramper Interaction

Abstract

The mechanism of mass loss during leatherwood-tramper interaction is dependent on the physical properties of the leatherwood bush. An equation describing the electrostatic charge buildup during the process is derived. Some tramper behaviour is analysed in the light of this phenomenum.

Introduction

The problems relating to the restriction of human passage through alpine scrub (Harper, I896) and leatherwood (e.g. Law, 1975) in particular have been recognised through out the ages. Leatherwood often features in the Folklore and poems of the hills (e.g. Spearpoint, 1975). Pointedly, leatherwood is not mentioned in a thesis on the salube by MacPherson (1974).

Little quantitative assessment of Leatherwood-tramper interaction (LTI) has been reported in literature. In view of the large areas of leatherwood in the local ranges a research institute has been established for the investigation of LTI phenomena. This paper describes how static charge is built up on trampers during LTI and derives an equation relating the variables for this. It also discusses some of the consequences of this buildup of charge.

Derivation of the Equation

Tramper is assumed to be a symmetrical object of total surface area S, totally immersed in leatherwood.

Area of one side is Equation .

Total volume of leatherwood displaced (sum of incremental volumes) is Equation where d is distance travelled in leatherwood field.

By Archimedes,apparent loss of mass M of tramper, Equation where D is mean field density.

However, because of the extremely abrasive nature of the medium, a proportion L of this M is actually lost.

Equation.where w and a are dependent on the state of the leatherwood and the armour of the tramper respectively.

L can be expressed as a sum,

L = L* + nm...2.where L* is mass of neutral particles lost; n is number of excess electrons lost; and m is mass of one electron.

Define a quantity F, the efficiency of excess electron production.

Equation

Substituting and rearranging in 1. and 2.,

Equation

Therefore total charge Q on tramper is

Equation DSd where c is charge on one electron.

Conclusion

The equation Equation. DSd describes how charge is developed on a tramper during leatherwood-tramper interaction. It may help trampers avoid some unfortunate side-effects of traversing some hill country.

However, nothing is known of the maximum charges or charge rates or the decay of such charge accumulations. Nevertheless steps are being taken to install charge neutralisers at main road ends, and in strategic locations on the tops, of the Tararuas at least. These will be totally unobtrusive, and obviously more desirable than wholesale destruction of our native and intrinsically beautiful leatherwood areas.

J.R.Keys ( Technical Institute of Tramping Sciences.

Acknowledgements are due to members of Vuwtc for their sometimes willing, sometimes unwilling cooperation in the field; to Mr B.A.Sissons who refereed this work; and to Whatneys Hyperbolical Association for Research in the Realms of Yokels, for financial support.