Una Imbarcazione a Vela Può Considerarsi Un Sistema Organizzato Di Attività, Attrezzature

Title: Evaluation of tasks and postures of a sailing yacht tailer

Authors: Di Bucchianico Giuseppe, Vallicelli Andrea

IDEA department, University of Chieti-Pescara

viale Pindaro 42, 65127 Pescara, Italy

Keywords: sailing yacht, tasks, postures, design

Topic: Design and usability

Abstract

A sailing yacht can be considered an “organized work system” defined by an interrelated set of elements (activities, riggings and people), working in special environmental conditions, pursuing the main object of “sailing” with efficiency, effectiveness and with satisfaction for everybody. On board, each hand has several defined roles, duties and tasks: these are carried out by interacting with specific riggings in specific “areas” of the sailing yacht. However, these “stations” not always derive from a user centered design: they often derive from compromises, which usually are aesthetical or simply hierarchical, in regarding with other emplacements on board. As a matter of fact, the most efficient design, from both an organizational and a postural point of view, does not always match to a “good-looking cockpit”, that is “aesthetically” interesting.

This paper outlines the results of an evaluation test referred to the tasks and postures of a tailer, who is the determinant subject taking care of furling and setting the sails.

The target of the evaluation test was to point out the most important aspects of a tailer’s postural discomfort, in order to define some guidelines referring to different operative conditions (postural, organizational and positional) as well as to different sets of rigging.

The study started from some methods and protocols referred to HTA (Hierarchical Task Analysis) and to OWAS (Ovako Work Analysis System): an integrated and original use of both is setted, in order to analyse the different tailer’s postures taken up in rapid succession, in comparison with the tasks connected to the most important riggings of a sailing yacht. This has been done in regards to different kinds of cockpits and uses of riggings.

Fist of all a theoretical analysis has been carried out, referring to some indications got from the wide literature on the subject. Afterwards an evaluation test with different subjects has been carried out, by registering the times of performance and the different taken up postures.

The experimental results allowed to provide some guidelines to favour and to guide design choices on postures, stations and riggings referred to the tailer’s role. At the end, guidelines are enforced in an interesting aestetic solution of a cockpit.

1. Introduction

In every human organized work system, the joined approach of Ergonomics and Work Organization reveals to be a formidable mean to increase the system productivity, improving at the same time the quality of lifestyle. Moreover, they together contribute to reduce injuries, errors, stress and strains and to enhance the satisfaction and care of fellows engaged in the group activity[1].

A sailing yacht can also be considered an “organized work system” defined by an interrelated set of elements (activities, riggings and people), working in special environmental conditions, pursuing the main object of “sailing” with efficiency, effectiveness and with satisfaction for everybody. On board, each hand has several defined roles, duties and tasks: these are carried out by interacting with specific riggings in specific “areas” of the sailing yacht. However, these “stations” not always derive from a user centered design: they often derive from compromises, which usually are aesthetical or simply hierarchical, in regarding with other emplacements on board. As a matter of fact, the most efficient design, from both an organizational and a postural point of view, does not always match to a “good-looking cockpit”, that is “aesthetically” interesting.

2. Purposes of research

Among the most important roles on board of a sailing yacht, the “tailer” is the determinant subject taking care of furling and setting the sails.

This paper outlines the results of an evaluation test referred to the tasks and postures of a tailer. The target of the evaluation test was to point out the most important aspects of a tailer’s postural discomfort, in order to define some guidelines referring to design of different operative conditions (postural, organizational and positional), as well as to different sets of rigging.

3. Method

The research was experimentally organized into three different phases: during the first phase data and information were collected concerning both in the large the navigation with a sailing yacht as long as the one studied, and the role, the riggings and the tasks of a tailer; in the second phase theories and methods were deeper examinated in order to analyse tasks and postures of subjects working together in organized systems and to apply these methods in an original way to the theorical evaluation of a tailer’s tasks and postures; in the third phase a direct observation was planned in order to verify the rightness of theoretical data of the preview steps and in case to point out any critical points. The study was completed with a comparison of data collected during the different phases: this allowed to define some guidelines referring to design of a tailer’s emplacement inside a sailing yacht cockpit.

3.1 The tailer’s role and riggings

The study started collecting data and information mostly from nautical literature, concerning both the operation’s principles of the propelling system of a sailing yacht ( reaches, riggings and common practises), and the different roles of the crew in a sailing yacht as long as the one studied. Since the study concerns with group activity in reduced spaces, this fact was important also to begin to understand the kind of direct and hierarchical relations between the tailer and the rest of the crew and between him and the different parts and riggings of the sailing boat interacting with him. Moreover, the first phase of the research was useful to collect initial information on the most usual tailer’s postures compared to the reaches, to the intensity of strains and to the kind of cockpit.

3.2 Tasks and postures analysis

starting from some methods and protocols referred to HTA (Hierarchical Task Analysis) and to OWAS (Ovako Work Analysis System), an integrated and original use of both was setted, in order to analyse the different tailer’s postures taken up in rapid succession, in comparison with the tasks connected to the most important riggings of a sailing yacht. In particular, from nautical literature have been collected usual tailer’s tasks and schemes during the principal riggings ( bearing away, turning, luffing and gybing); later, thanks to the experience of old-timer yachtsmen, it was possible to piece together the riggings temporal sequences, according to the HTA approach. Four different “fixed plan sequences” derived, in which each task follows the fulfillment of the preview. Moreover, for each step of the tailer’s task sequences a lenght of time has been supposed, and a Owas postural evaluation has been carried out, in regards to different kinds of cockpits and the tailer’s typical postures.

3.3 The experimental evaluation

Afterwards, a direct observation was planned and developed. The purpose was to verify the correctness of theoretical data and hypotheses collected in the previous phases (task sequences, postures, times of performances), and, if proper, to point out any practical skills and unusual postures, which was not mentioned by the specific literature.

In particular, six users were observed (three skilled ones and three not skilled ones) while acting as a tailer during the four rigging previously analysed (bearing away, turning, luffing and gybing): times of performances were measured and postures were observed, using original observation assessment surveys. On the whole they were 24 posture’s observation and 24 times of performances.

4. Major results

The experimental results collected in the third phase basically allowed to validate the previous theoretical setting referred to the task sequences.

Regarding some critical levels of the tailer’s postures deriving from a theoretical application of the Owas method, a fundamental reduction of them was noted: this because of the very short lenght of time of many tasks (about 1-3 seconds), that basically reduces their level of discomfort.

Only for some tasks and postures, referring above all to the use of winches, the direct observation confirmed the same critical levels of the Owas analysis.

Therefore, regarding the use of winches, further careful considerations were worked up, according with some problems emerged from the direct observation.

Afterwards it was possible to define some guidelines to favour and to guide design choices on postures, stations and riggings referred to the tailer’s role using whinches.

The research ends with a possible design application of guidelines, enforced in an interesting and innovative aestetic solution of a cockpit.

5. Implications

The research was developed within a degree thesis of industrial design, at the faculty of Architecture in Pescara. The dissertation title was Naked 55. A 17 meters long sailing yacht for open sea; relator Prof. A. Vallicelli, correlator Prof. G. Di Bucchianico, graduand student Marco Scuderi. The graduant student designed and carried out the test with the supervision of prof. G. Di Bucchianico. This paper, summarizing the purposes, the development and the major results of the research, was written by Andrea Vallicelli (introduction) and by Giuseppe Di Bucchianico (the remaining parts).

6. References

Corlett, N., Di Martino, V., Work Organization and Ergonomics, International Labour Office, Geneva, 1998 (Italian tr.: Organizzazione del lavoro ed ergonomia, Franco Angeli, Milano, 1999)

Shepherd, A., Hierarchical Task Analysis, Taylor & Francis, London, 2001

Tosi, F., Progettazione ergonomica, Il Sole 24 Ore, Milano, 2001

[1] Di Martino, V., 1998