Progress on the Vertical Electro- Optical Cable P.Kooijman UU/UVA/Nikhef

Design criteria Low drag ≥11 fibres Fibre break-out at each floor Two copper conductors DC/DC converter incorporated  Pressure Balanced Oil Filled Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 2

Present design Two halves 6.3 mm LDPE tube 12 Draka G.657 single mode Bend Bright fibres 2 AWG18 copper conductors (insulated) Siemens Midel 7131 oil. Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 3 Bottom of String Module 2 fibre penetrator Break-Out Box Break-out Electro- Optical cable 1 fibre penetrator 11 fibre penetrator DOM Optical Fan-out Module Bottom HalfTop Half

Break-Out Box (BOB) Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 4 VEOC in VEOC out BEOC vent DC/DC converter Oil filler hole closed after VEOC filled O-ring VEOC part BEOC part

BOB in real life Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 5 BOB totalTop of Penetrator Fibre container with oil filler BEOC flange

Penetrator Decided to go with conventional nut secured penetrator rather than conical plug Main reasons are for ease of assembly Also plug turns out to be quite fragile (scratches) Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 6 HIER WERKTEKENING

Penetrator in real life Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 7

Test - 1A VEOC had somewhat different design BOB Glue used  Now welded – Much more reliable and a lot easier and more pleasant – Consultant PE welding Fibre and Copper routing same as now. No Break out, just BOB Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 8

Assembly of VEOC 9Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC

Test at 5000 m Deployed vertically at 5000 m depth in Atlantic Measured attenuation in fibres Checked for leaks Pressure distribution over cable Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 10

Test – 1A Pressure has effect but.... – One side affected before submersion – Test while dismantling boxes showed return to ~0db when other container was opened – Fibres inside containers were probably pinched and were very sensitive fibre – Effect could be mostly reproduced in the lab The cable survived in tact and did not leak Doesn’t need kit gloves Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC m bar db

Schedule At present 3 cables (i.e. 6 halves) are being prepared for the deployment tests in April – Two will have only copper for the first mechanical tests – One with fibre also and with full breakout to DOM Spheres PPM-DU cable follows Marseille January 2013 KM3NeTcollaboration meeting -- Progress on VEOC 12