ESD_Feasability_Assesment.docx

Surface Forces Logistic Center SFLC Phone 410-762-6959 707 East Ordnance Road Baltimore, MD 21226 Fax 410 762-6203

ESD Assessment & Input for Technical Documentation Review: 87 ft CPB 24VDC Feasibility Study Technical Report.

Activity 21285: Technical Documentation Review of 24VDC Feasibility Study Technical Report, 87 ft CPB

Below are Electrical Systems Section comments on the documentation provided in response to Activity No. 21285.

1.) Subject Feasibility Study was reviewed by the Electrical Systems Section. Attached comments are provided . Recommendations on individual options as well as a composite recommendation of a final scenario are also provided in response to this Technical Report submission.

2.) Summary of Comments: Each of the three Scenarios presented have advantages and disadvantages to their implementation. Comments are provided to the overall application as well as comments on each of the individual cases that are presented under each scenario.

ESS Comments pertaining to Technical Documentation Review of 24VDC Feasibility Study Technical Report, 87 ft CPB

General Comments pertaining to all Three Options:

1.) The Load Analysis for the 12VDC Panels not provided in accordance with Statement of Work Requirements, Section 2.1, Part I, Paragraph 4 b.

2.) While the ship check findings are listed and the discussions have been documented, absent is a summary report of which conclusions have driven the decisions that have been arrived at for the three solution options presented. A synopsis of all gathered information is required by the scope of work that provides conclusions that are the basis for the three design options being presented. What is provided in the subject report is a summary list of some items that were discussed with different individuals followed by the three proposed solutions.

3.) None of the three options presented contain any discussion of how the new equipment will be fitted into the vessel. The proposed changes in the battery banks will consume a substantial amount of space and must be integrated into the vessel with minimal impact. The three options provided do not address this aspect of the study in any manner nor address the other additional equipment that is being added. There has been a general statement made in the narrative on page 11 concerning equipment installation but based on this brief discussion, there has not been appropriate consideration given to the arrangement and installation of the additional equipment.

4.) Activity 16217 is currently In Progress to replace the LaMarche and McCarron battery chargers with a Newmar Model PTMS-24-67 from WPB 87301 thru WPB 87366. This model is equivalent to the model installed on WPB 87367 and following in the product line from the shipyard. Based on the data contained in the load analysis provided with this feasibility study, the highest loading that is indicated within all of the loading conditions presented is 31.25 amps. That figure illustrates that a 67 amp battery charger would be sufficient to support the charging and operating requirements. Contact with a Newmar manufacturer representative confirms that the subject charger is capable of operating as a power supply and providing full rated current continuously. This concludes that regardless of which scenario was selected, removal of the 67 amp battery chargers and the addition of the 95 amp chargers, as suggested in the feasibility study, would not be required.

5.) Review of these three scenarios reveals that there are currently four alternators and five battery chargers utilized for charging the battery banks that will be contained in each proposed installation. The use of four alternators would contribute in excess of 200 amps of charging capability. Coupled with two 95 amp battery chargers and two 45 amp battery chargers, this will yield over 480 amps of charging capacity for the battery banks. Additionally, the Newmar Part No. PT-24-45 and PT-24-95U battery chargers proposed are capable of charging three banks simultaneously and are also capable of being used as a regulated power supply. An alternative approach may be to provide alternators on the two main engines and connect each of them to a single input, triple output battery isolator, Newmar Part No. 1-3-120, to allow charging of the respective engine starting battery bank as well as two other battery banks from each of the alternators. Coupling this with the Battery Charger suggested approach outlined in item 4 above, results in the charging solutions that are needed to make this change address the issues on the Cutters. This would result in a substantial cost and weight savings while providing a substantial supply of 24VDC power (166 amps) even without the generators running and the battery chargers operating.

6.) Review of the Load Analysis sheet pertaining to the Engine Room 24VDC Load Center Panel indicates line item loads listed for the alternate supply to the Pilothouse 24VDC Panel and the 24VDC SSDG Panel as emergency feeds. Should these loads really be listed in this manner? Each battery bank provided for each of the panels should be sized to support the panel connected loading and not alternate loading through the feeds supplied to other panels. The idea of providing an alternate feed to each of these panels is a good idea, but should be kept in proper perspective. An alternate feed is to be used for unexpected problems during normal operations and maintenance purposes but should not provide power to these units for extended periods of time and should not be used for emergency conditions. The same logic applied here should apply to the feed from the Pilothouse 24VDC Load Center Panel that is providing an alternate power source to the 12VDC Load Center Panel. This should not be listed as an emergency load on the Pilothouse 24VDC Load Center Panel.

7.) As a follow up to Comment 6 above, the Load Analysis for the Engine Room 24VDC Load Center Panel only accounts for the alternate feed loading to the Pilothouse 24VDC Panel and the 24VDC SSDG Panel under the emergency load condition of the load analysis. This loading scenario should be considered but should be accounted for in one of the normal operating conditions in order to ensure that there is sufficient power available to supply this load. For example, the Engine Room 24VDC panel has a load of .48 KW in the Winter Functional operating condition. This is equal to approximately 20 amps load on this panel in this condition. Should the Pilothouse 24VDC LC Panel be connected via the alternate supply in this same condition, this would add an additional .72 KW to the panel. This would be equal to an additional 30 amps for a total of 50 amps load in the Winter Functional operating condition. The Battery Charger and Battery feeding this panel should be capable of providing the full 50 amps continuously to this panel to allow this alternate power connection to be made without disabling the system should it be required.

8.) Batteries that are indicated in the Master Equipment List for scenario 1 through 3 are called out as Optima D31M rated with 900 CCA, 75AH capacity. These are Marine Deep Cycle batteries superior to the batteries currently installed on the cutter. However if battery replacement is to occur it may be more efficient to use the largest capacity battery that is available. Lifeline offers an alternative AGM battery that is approximately the same physical size as the Optima Battery but has a rating of 700 CCA with a 150AH capacity. This alternative recommendation is twice that of the Optima batteries proposed. In addition the Lifeline battery offers a superior warranty than that offered with the Optima battery.

Scenario 1 Comments:

1.) During the review of the Load Analysis for this scenario, there are some conflicts between the Load Analysis for the items on the two MDE Panels and the Engine Room 24VDC Load Center Panel being proposed and what is shown on the One Line Diagram for these panels. The Load Analysis for the MDE Panels indicates “Port Gen Control Panel”, “Port RCS-5 Remote Operating Sta.” and “Port RCS-5 Gearbox Cont. Unit” on this panel while the One Line Diagram indicates “Port RCS-5”, “Port MDE CCS Box” and “Port Gear Control Box”. Stbd is the same as what indicated for the port. The Load Analysis for the Engine Room 24VDC Load Center Panel indicates “Port RCS-5 Gearbox Cont. Unit”, “Stbd RCS-5 Gearbox Cont. Unit”, ”Port RCS-5 Remote Operating Sta.”, ”Stbd RCS-5 Remote Operating Sta.”, “Port MDE CCS” and “Stbd MDE CCS” on this panel while the One Line Diagram indicates “Port MDE CCS Box”, “Stbd MDE CCS Box”, “Port Gear Control Box Unit”, “Stbd Gear Control Box Unit”, “Port RCS-5” and Stbd RCS-5” These circuits and descriptions should agree with one another. In addition to this discrepancy, the load for the normal and emergency connection appears to be different. The normal load indicated on the Port Gen Control Panel is indicated as .05 KW on the 24VDC MDE Panel while the load indicated on the Port MDE CCS is indicated as .43 KW on the Engine Room 24VDC Load Center Panel. These loads should be the same on the normal and emergency supply.

2.) Connection of the Engine Room Load center to the Main Engine starting batteries is inconsistent with CG design practice. ABS Guide for Building and Classing High-Speed Naval Craft, 2007 Part 4, Chapter 8, Section 2 Paragraph 11.17.3 Miscellaneous Requirements states: “The starting batteries (or set of batteries) are to be used for starting and for engine’s own control and monitoring purpose only”. Application of this practice will aid in a design that corrects the problems that are presently being experienced. Additional equipment sharing the starting battery is the basis for some of the problems currently being experienced on the Boat and replicating this operating condition could result in the same issues being experienced.

3.) Selector switches indicated for use with the Engine Room 24VDC Load Center Panel, the 24VDC SSDG Panel, the Pilothouse 24VDC Load Center Panel and the Pilothouse 12VDC Load Center Panel are not contained in the Table 1 Master Equipment List (Scenario 1). Are the existing switches intended to be reused to fulfill the material requirements in this application? Implementation of this proposed Scenario requires the replacement of the existing battery disconnect switches with appropriately sized make-before-break switches. This is to insure continuity of power during a changeover from one power source to another. Impact on the Electronics and Navigation equipment may occur. In the case of the control power for the SSDG engines, likely unintended shutdown of the SSDG prime mover when changing over from one bank to the other due to the break in power when changing switch positions is predictable.

4.) It is noted that the Main Switchboard Control Power is connected to the 24VDC SSDG Panel. Recommend powering this circuit from the Engine Start Batteries or directly from the Generator Starting batteries just to ensure continuity of power should the selector switch be inadvertently left in the “Off” position.

5.) There are two 120VAC/24VDC converters shown to provide power to the MDE panels. The load analysis indicates that the cruising load for these panels is only 4.83 amps. The use of these converters in this application is really not required. Sufficient power for these panels can be obtained from one of the three outputs on the new battery chargers. Each charger is provided with three output connections and each of the new chargers being proposed is capable of being used as a power supply as well.

Scenario 2 Comments:

1.) Connection of the Engine Room Load center to the Main Engine starting batteries is inconsistent with CG practice. ABS Guide for Building and Classing High-Speed Naval Craft, 2007 Part 4, Chapter 8, Section 2 Paragraph 11.17.3 Miscellaneous Requirements states: “The starting batteries (or set of batteries) are to be used for starting and for engine’s own control and monitoring purpose only”.. This is the basis for some of the problems currently being experienced on the Boat and replicating this operating condition could result in the same issues being experienced. The original concept of the segregated starting batteries is an excellent idea; the addition of the switch to connect the starting batteries to the batteries supplying the engine room panels may compromise the intended solution.

2.) Selector switches indicated for use with the 24VDC SSDG Panel, the Pilothouse 24VDC Load Center Panel and the Pilothouse 12VDC Load Center Panel are not contained in the Table 2 Master Equipment List (Scenario 2). Are the existing switches intended to be reused to fulfill the material requirements in this application? Implementation of this proposed Scenario requires the replacement of the existing battery disconnect switches with appropriately sized make-before-break switches. This is to insure continuity of power during a changeover from one power source to another. Impact on the Electronics and Navigation equipment may occur. In the case of the control power for the SSDG engines, likely unintended shutdown of the SSDG prime mover when changing over from one bank to the other due to the break in power when changing switch positions is predictable.

3.) It is noted that the Main Switchboard Control Power is connected to the 24VDC SSDG Panel. Recommend powering this circuit from the SSDG Start Batteries or directly from the SSDG Deep Cycle Battery Bank just to ensure continuity of power should the selector switch be inadvertently left in the “Off” position. Also worth noting is that with the selector switches as outlined in comment 2 above, likely unintended shutdown of the Load Center Switchboard when changing over from one bank to the other due to the break in power when changing switch positions is also predictable.

Scenario 3 Comments:

1.) During the review of the Load Analysis for this scenario, there are some conflicts between the Load Analysis for the items on the two MDE Panels and the Engine Room 24VDC Load Center Panel being proposed and what is shown on the One Line Diagram for these panels. The Load Analysis for the MDE Panels indicates “Port Gen Control Panel”, “Port RCS-5 Remote Operating Sta.” and “Port RCS-5 Gearbox Cont. Unit” on this panel while the One Line Diagram indicates “Port RCS-5”, “Port MDE CCS Box” and “Port Gear Control Box”. Stbd is the same as what indicated for the port. The Load Analysis for the Stbd 24VDC MDE Panel Engine Room indicates “Stbd RCS-5 Gearbox Cont. Unit”, ”Stbd RCS-5 Remote Operating Sta.” and “Stbd MDE CCS” on this panel while the One Line Diagram indicates “Port & Stbd MDE CCS Box”, “Port & Stbd Gear Control Box Unit” and “Port & Stbd RCS-5” on the respective Port & Stbd 24VDC MDE Panel Engine Room. These circuits and descriptions should agree with one another.

2.) The four circuit panel that is connected to the 120VAC/24VDC Converter No. 1 is mis-labeled as being “Stbd 24VDC MDE Panel Engine Room”. This should be Port. Please revise or clarify as necessary.

3.) Use of the two 120VAC/24VDC Converters in the port and starboard engine room are not needed. These panels could be connected to the respective engine start batteries to provide the required power. This would ensure that there is both primary and back-up power for the Main Engines even if the generators are not in operation. The load analysis indicates that the functional load for these panels is 8.46 amps and the cruising load for these panels is only 4.83 amps. Sufficient power for these panels can be obtained from one of the three outputs on the new battery chargers during normal operation. Each charger is provided with three output connections and each is capable of being used as a power supply.

Composite Scenario and Overall Recommendation:

The Composite Scenario being offered is derived from the options presented in the technical report, coupled with some minor revisions to come up with an overall solution that satisfies the requirements I in the scope of work. The following narrative is provided to explain the Scenario being presented in some additional detail.

1.) The Main Engine and Generator battery arrangement has been taken from the basic format presented in Scenario 3. The major differences are that there is not a separate battery for starting of the SSDG’s shown in this Scenario. Having two completely isolated starting batteries for the main engines should ensure that there will always be sufficient power for starting at least one of the main engines. Once the main engines are started, the alternator will ensure that there is charging current available and sufficient power to operate all the vital loads that will need to be operated. One additional provision that is included in this Scenario is that there is a battery switch, Blue Sea part no. 11003, will allow a selection between either battery bank for engine starting and generator starting. The proposed batteries for this arrangement will not be the Optima batteries identified in the Option 3 Scenario. This proposed configuration will be utilizing four Lifeline, Model GPL-3100T Engine Start Batteries arranged in a Series-Parallel configuration. This will provide 1900 CCA at 32 degrees F.

2.) The battery isolator arrangement shown in Scenario 3 has been utilized, with one exception. Rather than using a one input, two output isolator on each main engine alternator a one input three output isolator has been utilized. This will provide a connection to the starting batteries, the MDE panel batteries and to the battery bank for the Engine Room panel as well as a connection for the Pilothouse panel. Each alternator will supply between 60 and 83 amps which translates to more than 20 amps charging capability for each of the three battery banks being supplied by each of the alternators. Having this in addition to the battery chargers when the generators are in operation will ensure a rapid recovery time on each of the battery banks being supplied. The proposed isolator for use in this application is a Newmar Model 1-3-120 or suitable equivalent.

3.) The panel arrangement for the main engines and engine room being utilized has been implemented from the arrangement provided in Scenario 2 with some minor modifications. Using this arrangement allows all of the vital control power for the engines and generators to be supplied from dedicated battery banks that are connected to the alternator supply from the main engines. Each of these will supply primary power for their respective engine as well as alternate power for the other engine. The Batteries supplying the panels that are included in this proposed option are Lifeline Part No. GPL-30HT Batteries that will provide 150 AH reserve capacity at the 20 hour rate. This will include the two banks that are supplying the new 24VDC panels for the Main Engines as well as the 24VDC Engine Room panel that will supply the other 24VDC engine room loads. The proposed battery chargers to be provided for all three applications will be Newmar Model PTMS-24-67. As outlined in the discussion above, these chargers are capable of providing regulated power during normal operations. Each of the Engine Room 24VDC panel battery banks are also supplied with the alternator connection that was discussed in comment 2 above. Steering gear power and SSDG Control power is provided from the same panels that are providing the Main Engine control power in order to provide the greatest continuity of power that is available. Additionally, an alternate power source has been added to provide back-up power for the Alarm & Monitor System and the Main Switchboard should these be desired. The alternate power source for the Pilothouse 24VDC panel has been relocated to the Engine Room 24VDC panel as to not put any undue additional loading on the batteries for the vital propulsion control power. An alternate supply has also been provided to the Engine Room 24VDC panel from the Pilothouse Panel should this be needed.

4.) The logic for powering the Pilothouse 24VDC panel has been derived from the layout that is consistent throughout all three Scenarios. The only exception being this Scenario provides an alternator power connection from the port main engine alternator to the Pilothouse battery bank that was not previously provided in any of the three scenarios presented in this study. In addition to the additional charging connection, the proposed batteries to be used in this scenario are Lifeline Part No. GPL-30HT Batteries, otherwise the same basic layout has been carried over to this plan.

5.) Other changes worth noting that have been included in this compromise are that there are no alternators being indicated on the Generators. Due to the amount of charging current available through the Main Engine alternators (160 amps plus) along with all the battery chargers, inclusion of the alternators on the Generator Engines is not required. All five proposed engine room battery banks can have up to 150 amps of charging current available to them with a generator running. Providing the additional alternators would amount to attaching a large weight to carry around on the generators. Another difference is that all the switches that are indicated are going to be Make-before-Break switches to insure continuity of power.

6.) An investigation was conducted on board CGC IBIS, WPB 87338 to determine the feasibility of the arrangement of the components being proposed in this scenario. Based on the arrangement observed on IBIS, it is feasible to add the new batteries as proposed. There is sufficient room to mount the engine start batteries in the same location as the current battery banks, port and starboard. The batteries for the Port and Starboard Engine Room panels can be mounted directly above the start batteries. This will require relocation of the tool box that is located above the batteries on the Port Side There is also sufficient space in the console to accommodate the new larger battery bank and charger being proposed as well. As a result the IBIS ship check, replacement of the current 24VDC panel located on the starboard outboard area of the engine room is recommended. This would allow installation of a more compact 24VDC Panel to take the place of the rather large panel that is there currently. Also noted during the ship check was that there appears to be sufficient room to mount new higher capacity batteries in the Pilothouse Console. That would allow the use of the proposed Lifeline Part No. GPL-30HT batteries which would provide a reserve capacity of 150 AH., The three scenarios proposed all include the addition of a new 24VDC Panel in the Pilothouse. The IBIS ship check raised concern as to where this proposed addition would be located? The only possible location that was noted during the investigation would be to add it inside the console, which is a less than optimal location. Photos of the areas observed are provided as well as a sketch of the proposed new battery basic arrangement.

7.) There are other items that need to be considered that are not mentioned in any of the proposed scenario options provided. First is that all battery installations need to include battery hold down capability. That is provided in this recommended scenario. This can be in the form of straps or mechanical hold down mechanisms, whichever is appropriate. Second is that the cabling connections to the batteries need to be made utilizing a much more flexible cable than what is currently used on the vessel. Use of LSSHOF and LSDHOF type cable will allow smaller bend radius on cables and will also provide a much greater flexibility in the cable routing. The configurations that are being proposed, will require more connections to be provided at the Starting Battery Banks. A connection such as a Marathon Part No. 1452301 will provide for multiple cable connections, or simply using a bus bar configuration on the battery terminals will help alleviate this issue as well. Finally, a brief cost summary as well as major weight additions and reductions are provided at the end of this document to support the equipment changes that are being proposed in this composite scenario and to aid in weight and moment calculations that may need to be performed in support of this feasibility study.

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