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CAMBANDSBuddy Twinning Bands
SO HOW DO YOU GO ABOUT TWINNING UP a typical pair of independent cylinders that you might find at a dive centre abroad Well, you could take a set of steel bands and a spanner with you, but I prefer to use Buddy Twinning Bands and Blocks.
     This is far from a new product, but I wanted to revisit it in Tests simply because I have heard all sorts of ill-informed comment about the use of these items and feel the record should be set straight.
     Believe me when I tell you that they really work - provided that you have a BC or wing with the requisite four slots in the backpack or backplate.
     I have heard people say that the ABS backpack that comes with Buddy BCs is not strong enough to take twin cylinders - to which I reply that has been using Buddy Twinning Bands for every project involving in-water regulator and computer comparisons since we started doing them more than 12 years ago. Never have I, or any of our test divers, experienced any problem with them.
     You simply substitute the single camband of your BC for a pair threaded through a curved block. A second pair and another block is used to stabilise the unit.
     Make sure that the bands are done up as tightly as possible and, as webbing can stretch when wet, that they are properly soaked first.
     Some Buddy wings, notably the Tech Wing and redundant Red Wing, have two sets of four slots so that the tank has maximum attachment, but even my old Buddy Trimix (now called a Trident) with only one set of slots works well with Twinning Bands and Blocks, even though the lower pair of bands is clamped into a totally arbitrary position on the tanks.
     The same can be said of all other Buddy BCs - they can all work with independent twins. Of course, if your tanks are connected by a manifold things are less than ideal. Presumably they will be already banded, in which case you can dispense with the blocks.
     So what about using twins that are totally independent Well, cave-divers have been doing that for years. You will need two separate pressure gauges, and to switch regulators during the dive, but whats hard about that Its the same as diving with two separate aqua-lungs; when others are going in with a single cylinder and regulator set, you have the security of two.
     I have even used two cylinders of different sizes, one 12 litre aluminium and one 15 litre steel. In that case I found I had to be a bit canny about how I arranged my weights so that I was not twisted to one side, but with identical 12 litre aluminium cylinders I noticed a slight pull to one side only when there was a 150 bar difference in remaining tank pressures.
     When rigging two cylinders, stand them upright on a flat surface and, after slipping the wetted bands over them, progressively tighten each side until maximum torque is achieved. After that, even if dried out, the tanks stay secure all week.
     The Blocks come in two sizes, to suit standard tall tanks or with curvature to suit squatter ÃdumpyÓ tanks. They take up little space in your luggage and their weight is of little consequence. You will need to take the extra regulator, however!
Buddy Twinning Bands and Blocks cost £39.
  • AP Valves 01326 561040, www.apvalves.com


  • Divernet Divernet
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    + Lightweight take-anywhere solution to twinning cylinders


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    - May not be ideal for use with manifolds