Direct Pipe Down Under – Recent Success and Opportunities

Abstract

Direct Pipe® (DP) was first introduced to the world in late 2007 with a 464m crossing beneath the Rhine River. Although still considered a new technology, as of March 2021, over 160 DP crossings have been completed globally with the popularity, and range of applications, growing rapidly since 2015. But what is Direct Pipe®? It is essentially unheard of in the southern hemisphere, with just three projects completed in New Zealand to date and the next closest project location being north of the equator in Thailand. Despite limited up-take of Direct Pipe® down under, the two longest DP crossings in the world (1929m and 2021m) have been completed in New Zealand by Australasia’s McConnell Dowell Constructors Ltd (MCD), who have over seven years of experience with DP and have completed their tenth DP crossing globally. This paper provides a brief introduction to Direct Pipe®, providing context around the range of applications where DP has established itself globally as a ‘go-to’ methodology for delivery of niche trenchless projects with otherwise unachievable requirements. This includes trenchless crossings with specific challenges of: shore approaches (outfalls); long drives deep below inaccessible areas; shorter, shallower drives beneath environmentally sensitive areas; or drives through ground considered too difficult for Horizontal Directional Drilling (HDD). Using McConnell Dowell’s project examples, the paper discusses the company’s approach to pioneering DP technology to overcome such specific challenges: maintaining safety and care always; sharing experiences in addressing difficulties; and achieving world records in doing so. Opportunities for niche application across Australasia is further raised for consideration.

Techniques