Updates to MIL-STD Electric Plant Installation Standard Methods for Surface Ships and Submarines

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1 Electric Plant Installation Standard Methods for Surface Ships and Submarines Presented at the National Shipbuilding Research Program Electrical Technologies Panel Meeting Charleston, SC March 9, 2017 Christopher Nemarich NAVAL SEA SYSTEMS COMMAND Electrical Systems Ships SEA 05Z32

2 MIL-STD-2003 Updates to MIL-STD-2003 Details requirements for standard installation methods employed for submarine and surface ship electrical distribution systems. Application to new construction, conversion, repair, and alteration of ships. Intended for use by all Navy installation activities, public and private yards, repair/maintenance depots, ships, including MSC and USCG. Divided into 5 Parts: Cable Equipment Penetrations Cableways Connectors MIL-STD-2003 has over 1,000 pages of procedures and methods 2

3 Reasons for revision to MIL-STD-2003 No comprehensive update since initial issue 24 June Updates for new electrical installation methods, ship design and construction techniques developed over the past 30 years. To include practices selected from the 2013 NAVSEA Enterprise Commonality Cost Reduction Review of Electrical Installation Standard Methods. To eliminate references to cancelled specifications and standards. To eliminate inconsistencies across procedures. Evaluate and incorporate changes recommended through the Command Standards change system. 3

4 MIL-STD-2003 revisions additionally include: NAVSEA approved methods from shipyard standard electrical installation methods drawings from: Newport News Shipbuilding Ingalls Shipbuilding General Dynamics Electric Boat Puget Sound Naval Shipyard SUPSHIP Gulf Coast Regional Maintenance and Repair Centers Implementation of current applicable versions of accepted commercial standards and practices. 4

5 Timeline Approval to proceed with development of MIL-STD-2003B Intermediate Review completed Final Review completed - October 2016 Released for Standards Review Board (SRB) - November 2016 Adjudication of comments - March July 2017 Issuance of MIL-STD-2003B (planned) 30 Sept

6 Significantly expanded list of reviewers for the SRB and included industry suppliers that support electrical installation methods to maximize feedback. Received significant comments from NAVSEA codes, shipyards, and fleet maintenance centers during intermediate review. Received over 500 comments to date from SRB. Comment adjudication with coordination across NAVSEA organizations and field activities. Each comment will be addressed and adjudicated individually. Goal Ensure accuracy and broad acceptance of methods and practices to be published in MIL-STD-2003B 6

7 1B Cables Added a new method (1D7) for repair of insulation directly over cable conductors if conductor is completely intact and NAVSEA approval is obtained. This was not allowed before. Added cable shielding requirements from VIRGINIA Class Standard Methods drawing, NAVSEA New methods for cable shield grounding, for splicing, and for cable repair. Based on newer technologies. Reinstated the use of thimbles for end sealing of existing connections to nonwater block cables with approval from the local authority. Based on input from SSGC that removing thimbles during overhauls is costly and unnecessary. Added new, alternate, less labor intensive, method for insulating connections for motors & transformers from SSGC drawing SP (1B10) Added methods for splicing 5kV cables (1E6) 7

8 1B Cables Allows for cold shrink sleeving as a substitute for heat shrink sleeving per the requirements of ASTM F1835 for splices of cables rated < 500 volts above the ship waterline where watertight integrity is not required. (Enterprise Commonality Cost Reduction item). 8

9 Cold shrink tubing is a more efficient method in cable splicing and jacket repair (limited implementation) Cold Shrink Comparison Process Review Heat Shrink Tubing Traditional heat source is used to repair cable jackets Process must meet hot work area restrictions Average labor time = 15 min Recommendation Detail Include industry standard cold shrink tubing methods in MIL-STD Require all future cable splicing and jacket repair methods employ lowest cost cold shrink tubing technology Cold Shrink Tubing Open-ended rubber sleeves are factory expanded and assembled onto removable plastic cores Core is removed allowing the tube to shrink and form a water-resistant seal Average labor time = 3 min Rationale / Savings Estimate The use of cold shrink tubing generates 80% labor savings relative to heat shrink tubing installation by eliminating the labor time required for hot work area preparations and the use of active heat sources during jobs 9

10 2B Equipment Added methods for bulkhead clip mounting of smaller electrical boxes. From the approved method 502-NG NNS Standard Methods Drawing NAVSEA Added detailed methods to illustrate bonding and grounding of equipment to meet MIL-STD-1310 requirements. Based on lessons learned from a new construction project. Added allowance to use junction boxes to extend power and signal cables to replacement components to avoid replacing a cable if the replacement component junction box is in a different location than the original junction box. The cabling between the extension junction box and the replacement component shall meet all requirements of the original cables. Updated fastener requirements, such as limiting the use of split ring lock washers. Based on analysis, testing and field experience. 10

11 3B Penetrations Updates to MIL-STD-2003 Added general methods for installation of bulkhead square frame back-to-back MCTs for certain protected bulkheads and decks. Based on Newport News Standard Methods Drawing. Added instructions for installing MCTs with the capability of providing EMC grounding. Based on method 616-NG Newport News Standard Methods Drawing. Add requirements for spare MCP area to support future growth. When installing new MCPs, at least 20 percent of the MCP usable area shall be reserved for future cable installations. Added retest requirements for MCP installation. Retest requirements for all MCP types changed to require airblast or vacuum box test for airtight, oiltight and watertight penetrations. Based on input from PSNS and SSGC. Added requirements, methods and figures for the Expanded Sleeve Multi-Cable Penetration Sealing System (RISE) system. 11

12 The RISE system is an approved installation method for Multi-Cable Transits (MCTs) RISE system components Process Steps Apply rubber sleeves Cable Runs Fill MCT with spare sleeve Apply sealant System Details RISE system utilizes specialized rubber sleeve that support various cables routed through MCT When exposed to fire or high temperatures, this rubber will expand to five times its original volume. Spare sleeves are inserted in the MCT to allow for the quick installation of additional cables to a the MCT FIWA is a fireresistant and water repellent sealant based on a single component silicone compound that expands to 10 times its original volume The RISE system allows for streamlined cable installation through MCTs that require fire resistant protection 12

13 4B Cableways Eliminates requirement for channel rubber for cable banding in certain circumstances as a labor and material cost savings. Specifies CRES 304 (nylon coated) or CRES 316 for cable bands for submarine outboard cableways. Corrosion of CRES 304 occurs as they are electrically isolated by channel rubber. Nylon coated CRES 304 is preferred due to superior corrosion resistance. Added methods to allow cable hanger extensions to avoid adding new cableways. Added methods for the use of Y-hangers. Based on Ingalls drawing SP002109, Non-Standard Cableway Methods. (Enterprise Commonality Cost Reduction Item) 13

14 Including Y-Hangers in MIL-STD 2003 will allow for significant reduction in material cost (implemented) Y Hanger Design Implications Current cableway intersection components Intersection is created using either 2 or 3 hangers based on the nature of cable runs Cableway Intersection = Recommendation Detail Add Gulf Coast approved Y Shaped hanger as the primary method used for creating multi-direction cableway intersections New cableway intersection components Baseline Future Savings Hangers Required Average Material Cost Per Intersection $90 $60 $30 Average Labor cost per intersection $150 $100 $50 Total Intersection Cost $240 $160 $80 Rationale / Savings Estimate Average hanger installation currently requires 2 hours of labor totaling 6 hours Reduction of 2 hanger installation will result in 66% labor savings in time allocated to cableway intersection installation 14

15 4B Cableways Allows stud welding for major cableways. Based on NNS Standard Methods Drawing for CVN s. (Enterprise Commonality Cost Reduction Item) Allowed use of Panduit banding for larger cable bundles for non-weight bearing applications with NAVSEA approval. Not approved for weight bearing applications with larger cable bundles - not shock qualified. (Enterprise Commonality Cost Reduction Item) 15

16 Stud welding is NAVSEA approved installation method for hanger attachment that can be expanded to main cableways (implemented) Stud Welding vs. Stick Welding Cost Opportunity Process Details Current Application Stud Gun Welding Stud arc welding, joins a stud and another piece of metal together using a capacitor discharge Limited to select applications in new construction across the fleet except Virginia class Traditional Stick Welding Standard 360 degree weld for trapeze and inverted T hangers Main cableways during new construction and repair Potential Future State Application ~Labor savings relative to traditional Welding 90% of hull hanger connections where technically feasible Extremely limited use in hanger connections 75% N/A Source: Shipyard Workshops 16

17 Employing the use of modern Panduit banding tools reduces labor required for cutting and securing banding material (implemented for main cableways) Cable banding process Place strap Apply buckle Tighten band Cut excess material Close buckle Avg. Baseline Time required with MIL- STD tooling Estimated time with Panduit tools 2 min 2 min 10 min 2 min 2 min 2 min 2 min 3 min 1 min 1 min Panduit banding tools Tools install extra-heavy.50" through super-heavy.63" cross section stainless steel metal locking ties Designed to reduce operator fatigue, promote worker safety, and improve productivity Source: Shipyard Workshops 17

18 5B Connectors Added restrictions to use of hazardous connector material consistent with NAVSEA letter Ser 05Z3/028 dated 06 December 2011 and MIL-STD-917. Acknowledges other connector types, other than the types specifically covered in MIL-STD , that may be called out for installation on drawings. For other connector types, such as RF, DB, and RJ connectors, class or specific ship installation drawings, provided by the ship design activity, should be followed for connector installation. Provides SAE AIR1651 instructions for guidance to determine the proper torque and tightness for assembling electrical connectors. 18

19 5B Connectors Added new method for Multi-Cable Connector Assembly using grommets (Figure 5C3) Based on an Electric Boat drawing approved by NAVSEA letter 9300 Ser 397T1F/0693 dated 22 July A CONNECTOR ADAPTER W/ O-RING BACKSHELL BACKING PLATE MULTI- CABLE GROMMET GROMMET FOLLOWER CLAMP ASSEMBLY BRANCH CABLES SEALING PLUG(S) GROMMET BACKING PLATE 19

20 Comments on revisions to MIL-STD-2003 should be sent before 17 March 2017 to: 20