1. String mechanics and production P.Kooijman,NIKHEF/UU Pylos, april 2007

2. How do we get signals out of sphere For readout to work need single optical channel connection between shore and OM Cable with 1 or 2 fibres per OM 2 copper per OM Need breakout at each OM

3. Solution being investigated Seacon equipresure “hose-cable” Routinely used Pressure insensitive fiber!! Connectors and feedthroughs relatively cheap

4. Design is flexible (more ways) Only small area where pressure needs to be held Cable is a tube filled with oil and whatever you want (gets bigger with more content) duct-hose optical/electrical contact block (vulcanized rubber) fibre copper twisted pair inert oil any combination

5. So how do we use it Thin structures filled with oil Hose with 2 fibers and two coppers Small hose connector Pressure resistant connector And bulkhead hoseconnectors Hose with many fibers cable

6. What else? At bottom of line we need container for DWDM After that can continue again with just 2 fibers Much cheaper (less expensive solution) at junction box Wet mateable copper only (2) Wet mateable fiber only (2) Splitter equipressure Hose connectors Pressure feedthrough connector many fibers DWDM JBJB 100m To OM 1km

7. Price? Dont know yet – but estimates come in at around k€ 11 for a floor with OM with 38 PMs including cable Only one end of interlink is wet mateable – no non-destructive recovery Split fiber and copper in wet mateable – lose very expensive connectors Sofar saving of about factor 2 per unit looks feasible

8. So how do we build 500 strings in 5 years?

9. Delivery 2000 glass spheres per year 80000 PMTs per year 100 500m cables with connectors fibres etc per year Delivery of tested entities

10. test report PMT PMT assembly characterize storage / transport assembled PMT-base OM assembly characterize connector mechanics central electronics STRING assembly characterize test report storage / transport cable mechanics assembled bottom instrumentation Assembly line

11. And of course Transport to the site Deployment at the site at rate of 2/week Deploy in containers Maybe more “daisy-chained” together (6?? With just 1 underwater connection)

12. Conclusions Cable with breakout and connector to sphere – OM can be separately built and tested – complete system test because of single connection from shore to OM Cable looks to be possible with OM supports and breakouts First look at production looks tough but never say never Needs significant organisation and delivery streamlining

13. PS 500 strings = 200 M € = 40 Antares = 2km 3

14. Where did we save/lose money 38 pmt (8kEuro) vs 4 10” (6kEuro)X20 1sphere(0.5kEuro) vs 4spheres (2kEuro)X20 Modulator + SER+DES (2kEuro) vs (0)X20 No (0 kEuro) vs 1 Ti cylinder (10kEuro)X20 Connectors (1kEuro) vs (5kEuro)X20 No connection at stringbottom (15kEuro)X1 Connectors to JB (5kEuro) vs (15kEuro)X1