One less use for Duct tape – diving umbilicals for the 21st Century

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Technology has had an immeasurable effect on the advancement of man’s quest to conquer his world. The capability to safely deploy a diver to 1500 ft of sea water and beyond is a testament to our ability to harness new materials and techniques in pursuit of knowledge and natural resources. Diver’s personal equipment from hats to fins has seen radical change and improvement over the years allowing safer more productive diving.

There is however one vital piece of a Diver’s gear that has remained virtually unchanged since the industry moved on from upturned buckets. I refer to the diver’s life support umbilical. In its simplest form this comprises a breathing gas supply hose, pneumo hose, communication cable and life line. More complex umbilicals include additional hoses and cables for hot water, lights, video and gas reclaim.

The traditional solution to combining these different elements together is to lay out a rubber hydraulic hose, an air tool line, a military surplus cable and a length of poly rope, then strap them all together with copious amounts of duct tape every foot or so.

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The familiar site of taped Umbilicals at a Gulf coast diving contractor.


Interestingly none of these components were originally designed for underwater use, much less diving, rather they were adopted on the basis of what was available at the time (early 1950’s). The most popular gas hose (Gates 33HB and similar), for example, conforms to the SAE100R3 (Society of Automobile Engineers) standard for hydraulic hose.

The military surplus cable (known as spiral 4) used as a comms. line has an uncertain pedigree but appears to originate from the Korean war, again not best suited to subsea use. The PVC jacket soon cracks in sea water, exposing the steel wire beneath and creating a handling hazard. This cable is a classic miss-application which has become so engrained in the industry (at least in the US) that when the surplus finally ran out dive supply stores rushed out and had the product manufactured to the same flawed specification. A truly unique case of retro-engineering!

Clearly the attraction of this type of umbilical is low initial cost, particularly if you discount the hours of manual labor needed (on the grounds that the shop hands or diver’s have nothing better to do!). What is less obvious and often ignored is the cost of maintaining these umbilicals. Duct tape is not cheap by the time you’ve re-made the same umbilical several times. Not to mention the cost of replacement components and labor (strike that – I forgot the labor is free!). Some in the industry will boast they can make a taped umbilical last years, this reminds me of the road sweeper who claimed to have made the same broom last 10 years, by only replacing the head 17 times and the handle 9 times!

Joking apart, how does this product actually perform? The answer is that it works, but barely. It’s heavy (in air and water), hard to handle (for diver and tender), apt to throw loops and snag, and generally fails prematurely.

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Typical 3-part taped umbilical construction, note the cross-overs and uneven bending
imposed on the components when coiled (even on a relatively large radius of  8”)



Is there a better solution? Fortunately there is – the cabled or “rope like” umbilical using purpose built components rather than military surplus and industrial hose. The concept is not new.  Rope-like umbilicals have been used for saturation diving since the 70’s and more recently have been adopted by the US Navy.

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3-part Diveline umbilical. Note how evenly components conform to the bend and the
elimination of a separate life line.



These umbilicals are engineered products designed specifically for the application. Like a rope the individual elements are spiraled around each other allowing them to adjust their relative positions during bending to eliminate stress build up due to differential lengths on the inside and outside of the bend ( see photo below). No one component sees excessive compression or tension and therefore is much less likely to be damaged, considerably increasing the life of the product.

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In addition to the simple cost savings of reduced maintenance and extended life, cabled umbilicals made from purpose-designed components offer very significant user benefits over traditional solutions;

  • They are kink resistant, smaller, more flexible and lighter both in air and water, and, depending on configuration, the buoyancy can be adjusted from slightly positive to negative depending on preference for any given job site. This reduces fatigue of both Diver and tender, improving overall efficiency (see comparison table below for  Diveline Flexflow gas hose vs R3 rubber).

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  • The components are “locked” into their spiral shape by the manufacturing process and have no tendency to separate, therefore eliminating loops that could become entangled, offering a major safety improvement. Long continuous lengths can also be produced eliminating hose joints for extended penetration dives.
  • The materials of the hoses and cable components are engineering thermoplastics that have exceptional strength, abrasion resistance and aging characteristics. In addition to their much longer lifetime in an underwater environment, they are available in vivid colors dramatically enhancing their visibility. They also have excellent chemical resistance and are easily cleaned making them ideal for diving in potable or contaminated water.
  • Should a component be accidentally damaged, replacing it is a simple process that still needs little or no tape. See photo below.

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Of course some in the industry have been heard to say “if the Navy’s using it, it has to be too expensive” and “we don’t have the budget for the good stuff”.

Naturally a high performance product is going to cost more out of the box but lowest cost of ownership has to be what counts. After all responsible Dive contractors want to educate their customers to differentiate between lowest bid and the overall value of the service provided. This makes good business sense and surely should apply to the equipment they purchase, i.e. best value not lowest price.

Given all of the safety and economic advantages and with the increased availability of these superior products, it is surely time to re-assess the “traditional” approach to the humble diving umbilical and reduce by one the things you do with Duct tape.

Colin Zak
President

HL Technologies LP
10711 Cash Road, Stafford TX 77477, USA

FOR MORE INFORMATION ABOUT UMBILICALS VISIT WWW.UMBILICALS.COM

Author Bio
A hose and cable industry veteran, Zak has been involved in underwater umbilical solutions for over 20 years. 16 of those were with JDR Cable Systems and its predecessor Jacques. He was president of the US operation of JDR, then formed Diveline in Stafford, near Houston, in April 2002. Diveline is a brand name for the diving umbilical products of HL Technologies Umbilicals International Division.

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