Cranfield University

Research Engineer: Peter Shipton

Supervisor: Dr Iain James, Centre for Sports Surface Technology, Cranfield University

Sponsors: England and Wales Cricket Board (ECB), Engineering and Physical Sciences Research Council (EPSRC)

Introduction

Cranfield University was asked by the England and Wales Cricket Board (ECB) to develop a detailed scientific understanding of the rolling of cricket pitches through independent research, and from that develop guidelines for pitch preparation by rolling to assist in the development of the sport.

Following four years of research, Cranfield University are soon to publish 'Guidelines for Rolling in Cricket' – aimed at both professional and volunteer groundstaff.

At the beginning of the project over 100 groundstaff across England and Wales were surveyed to determine how they rolled their pitches and it was found that the average number of passes in pre-season rolling in the club game was 83 passes per pitch and 53 passes in the first class game. However, some clubs only do five passes per pitch – the range in the first class game is 5 to 280 - and one person claims 540 passes! So, it seems there is plenty of scope for optimisation – not everyone could be getting it right.

(Pictured right: Peter Shipton conducting rolling research on the Cranfield University trial cricket pitches.)

Approach

Working with the ECB and the IOG (Institute of Groundsmanship) Cranfield engaged groundstaff in the research process throughout the project – and many were asking the same questions:

• How much rolling should I do?
• When should I start rolling and how long should I roll for?
• What is the best moisture content for rolling?
• What weight and diameter of roller should I use?
• How fast should I roll and in what direction?
• Can I damage the pitch by rolling?

Different approaches were developed to combine small- and large-scale laboratory testing with a range of field trials, using facilities unique to Cranfield University and its expertise in sports surface technology and agricultural engineering.

(Pictured above: More than 1,800 cores were extracted in the study of how rolling cricket pitches causes density changes through the profile in cricket pitches.)

This included taking more than 1,800 cores from trial pitches at the University and developing the Cranfield Cricket Rolling Simulator. This was used to analyse soil movement in pitches with a range of roller weights and diameters using new video image processing analysis.

(Pictured above: The Cranfield Cricket Rolling Simulator was designed and built at Cranfield to study the effect of roller design and soil and turf conditions on rolling effectiveness. Video processing software was developed to track soil movement under different rollers.)

Videos on  

• An overview of the Cranfield Cricket Rolling Rig and how it was used in the research
• Shrink and swell behaviour of clay soils
• The definition of a roller pass in the Guidelines for Rolling in Cricket

• Soil compaction under rollers is a function of: density, air filled porosity, moisture content, grass rooting, roller diameter and roller mass.
• Vertical deformation was elasto-plastic and maximum compaction for a particular combination of the above factors was achieved after only 4-5 passes of a tandem roller.
• Compaction limits for cricket rollers range from 1.5 to 1.6 g/cm³. Match pitch densities of 1.7-1.8 g/cm³ are possible but only by soil shrinkage during drying following compaction by a roller, not by the roller itself.
• There was no significant difference in grass root dry weight in soils of 1.4 to 1.8 g/cm³ in experiments where gaseous exchange was not limited, but roots were increasingly concentrated at the top of a 200 mm profile as density increased.
• There is a significant opportunity to increase efficiency of rolling in cricket and the methodology for this is detailed in the Guidelines for Rolling in Cricket.

Guidelines for Rolling in Cricket

 The 'Guidelines for Rolling in Cricket' by Peter Shipton and Dr Iain James are now available to download.

The guidelines are aimed at all Cricket Groundstaff and Clubs and combine an introduction to the science behind rolling and provide detailed guidelines for both pre-season and match pitch rolling.

For further information please contact Dr Iain James.