2023 Tailshaft Report and Readings from GMD.pdf

3617 Koppens Way

Chesapeake, VA 23323

Phone 757-558-3625

Fax 757-558-3627

Service Report

Job Number : F8097.001.40

Dates : 5-9-23 thru 6-10-23

Vessel Name : Kings Pointer

Vessel Hull Number : N/A

Location of Vessel : Brooklyn, New York

Vessel Owner : MARAD

Owners Rep. : Tim Mcgeein

Phone / Fax : 757-620-8480

E-Mail : timothy.mcgeein@dot.gov

Shipyard Rep. : Edgar Adams

Phone / Fax : 347-768-4853

E-Mail : eadams@GMDSHIPYARD.com

Purchase Order by : GMD Shipyard

PO Number : CIA

Installation Number : N/A

Drawing Number : 1547-4801

Tech Manual Number : H01702/03

Seal Type : 260 MKII

Class Surveyor Present : ABS

Naval Personnel present : N/A

Lead DMS Rep. : James Carter

DMS Rep. : James Armistead

DMS Rep. : N/A

3617 Koppens Way

Chesapeake, VA 23323

Telephone 757-558-3625

Fax 757-558-3627

Vessel: Kings Pointer

Date: 5-9-23 thru 6-10-23

Service Summary

Disassembly

DMS was requested to travel by GMD on 5-9-23 and arrived onsite to begin work on

5-10-23. DMS began by getting the chief engineer to pitch the blades to the Full Astern position and began draining CPP and Stern Tube Oil. While oil was draining DMS took bearing wear down readings in the presence of the Port Engineer and Chief Engineer. They were recorded in the chart located inside the box of the depth micrometer that stays with the ship.

Kings Pointer Wear Down Readings

TOP BOTTOM

STBD 60.10mm 61.30mm

PORT 60.65mm 60.65mm

DMS continued by disconnecting the O.D Box hoses and removing the O.D. Boxes from the vessel. Once this was completed the coupling bolts and split rings were labeled and removed. After removing the coupling bolts DMS noticed that several were damaged in the threaded and shank area and a CFR was submitted requesting new coupling bolts. GMD was tasked to machine all new coupling bolts out of 4340 High tensile steel using the removed bolts as samples. The split rings were removed allowing access to disconnect the outer and inner oil pipes. The next step was to disconnect the Hydraulic couplings to begin shaft removal.

Both shafts were removed from the vessel and loaded onto a trailer. Both shafts were then lifted off their supporting blocks by the crane to remove the Aft stern tube seals and liners as well as the tail shaft flange covers. Both shafts were then transported into the shop for complete disassembly.

DMS and GMD began by removing the aft portion of the hubs. Once removed DMS noticed that all the sliding blocks had been installed incorrectly by the previous service company and all the corners had been smashed and deformed. A CFR was submitted, and all new sliding blocks were machined to the correct dimensions based on the size of each yoke center post and each corresponding blade groove. The inner oil pipes were disconnected from the yoke and removed from the shaft. The forward hub assemblies were separated from the tail shaft flanges by removing the hub bolts and dowel pins. Both Port and STBD hub and yoke assemblies were blocked up on pallets for piston removal. To complete piston removal a bracket was fabricated for the Hy- Torque reaction arm that bolted to the hub using the hub bolts. Using the bracket, a 145mm socket, and a 10mxt Hy-Torque head DMS was able to remove both hub pistons without issue.

With disassembly complete DMS moved into the inspection process. All parts were cleaned, inspected, and measured. All measurements were taken and compared to OEM “In

Service” tolerances. All parts were within OEM specifications and no repairs were necessary to the hubs or blades at this time. The blades, blade bolts, hubs, hub bolts, hub dowels, servo pistons, yokes, tail shaft flanges and coupling areas were all dye penetrant tested with no indications present. The following pictures show the NDT inspection results.

Port Blades

STBD Blades

STBD YOKE

PORT YOKE

STBD HUB

PORT HUB

Port Hub Bolts and Dowels STBD Hub Bolts and Dowels

PORT and STBD MKII Seal Assemblies Each FWD and Aft seal assembly was disassembled, cleaned, and inspected. The aft seal assemblies were found assembled incorrectly by the previous service company as the #2 lip seals were installed backwards. All seal liners were cleaned and inspected and found to be in satisfactory condition however, the Fwd. seal liners will need to be replaced next docking.

All threaded holes were cleaned and chased. All machined mating surfaces were stoned to ensure flatness prior to assembly. Port and STBD MKII assemblies were re-assembled in accordance with the OEM drawings using new OEM bio-friendly lip seals. The serial numbers were recorded and are as follows:

FWD Lip Seal Serial Numbers

AFT Lip Seal Serial Numbers

*New Liners were purchased however they were unmachined and would not fit.

Due to time restraints and cost efficiency the existing liners were re-used. New Seal liners will need to be used during the next overhaul!!! *

Port STBD

# 4 Lip Seal (Aft Lip) 2602301079B 2602301077B

#5 Lip Seal (FWD Lip) 2602301080B 2602301078B

Port STBD

#3 Lip Seal (Fwd Lip) 2602207488B 2602207516B

#2 Lip Seal (Middle Lip) 2602207487B 2602207517B

#1 Lip Seal (Aft Lip) 2602207515B 2602207518B

Stern-Tube Bearing Survey

DMS performed a bearing survey that included a visual inspection as well as dimensional readings on the FWD and Aft Stern Tube bearings and their corresponding shaft journals. The visual inspection of each Fwd. and Aft bearing showed a small amount of radial grooving, as well as some minor linear marks. None of these groves or marks were excessive and warranted the recommendation of a bearing replacement. Each bearing surface was free of gouging and all babbitt was still intact and was visually in re-usable condition.

STBD Aft Bearing Port Aft Bearing

STBD FWD Bearing

Port FWD Bearing

The bearing and shaft journal measurements are as follows:

Port FWD Shaft Journal Dimensions

A B

Aft 8.983” 8.983”

Fwd. 8.983” 8.982”

Port FWD Bearing Dimensions

Design Dimension 8.996” A B

Aft 9.007” 8.997”

Fwd. 9.002” 8.993”

Port Forward Shaft to Bearing Clearance 0.010”-0.024”

STBD FWD Shaft Journal Dimensions

Aft 8.979” 8.979”

Fwd. 8.980” 8.980”

STBD FWD Bearing Dimensions

Design Dimension 8.996” A B

Aft 8.993” 8.992”

Fwd. 8.992” 8.995”

STBD Forward Shaft to Bearing Clearance .012”-.015”

Port Aft Journal Dimensions

Aft 9.171” 9.170”

Middle 9.170” 9.170”

Fwd. 9.171” 9.171”

Port Aft Bearing Dimensions

Design Dimension 9.193” A B

Aft 9.187” 9.184”

Middle 9.187” 9.186”

Fwd. 9.184” 9.186”

Port Aft Shaft to Bearing Clearance .014”-017”

STBD Aft Journal Dimensions

Aft 9.171” 9.170”

Middle 9.171” 9.170”

Fwd. 9.170” 9.170”

STBD Aft Bearing Dimensions

Design Dimension 9.193” A B

Aft 9.188” 9.185”

Middle 9.186” 9.186”

Fwd. 9.185” 9.185”

STBD Aft Shaft to Bearing Clearance .015”-.018”

* Due to the location of the intermediate shaft bearings no bearing survey was able to be performed. *

Assembly

Hubs DMS began by rebuilding the FWD and Aft hub assemblies. New high-pressure seals were installed in each hub assembly. New Port and STBD piston seals were installed prior to torquing the piston onto the yoke shafts. New locking set screws were drilled, locking the piston to the shaft of the yoke. The inner bore of the tail shaft’s were cleaned, and the inner oil pipes were installed. The FWD hub assemblies were mated to the tail shaft flange using new

O-rings. The hub dowels and hub bolts were installed, the hub bolts were torqued to OEM specifications. All hub bolts were drilled for new locking set screws as the bolts didn’t quite line up with the existing set screw holes. All blades were installed with new blade foot seals and newly machined sliding blocks. The Aft hub assemblies were installed, and the blade bolts were torqued to OEM specifications. The shafts were lifted off the shoring blocks to install the flange covers and aft seal assemblies. Each flange cover was installed using a new O-ring and both aft liners were assembled using a new O-ring and gasket. Both hubs were filled with EAL grease supplied by the chief engineer and transported to the drydock for installation.

Shafts The Port and STBD shafts were rigged into the vessel. The FWD. seals were slid over the fwd. end of the shaft and the shaft was carefully inserted into the coupling. The inner oil pipes were connected, and a new locking set screw was installed. The couplings were pressed up hydraulically to the same location they were removed from. The outer oil pipes were connected, and the split rings installed using new coupling bolts, castle nuts, and cotter pins.

While attempting to mate the Port side outer pipe DMS noticed that the tail shaft coupling flange and the reduction gear output shaft flange are misaligned. The tail shaft flange sits approximately 3mm high and 1mm inboard. Due to time constrictions 4 old coupling bolts were chamfered on the end and used as drifts to align the couplings. This was not a DMS recommendation, and the customer was made aware of the potential mechanical fatigue that could occur on both the stern tube bearings and the reduction gear box bearings.

Seals The Aft seals were mounted to the stern tube and the shaft was rolled to check alignment. The forward MKII seals were mounted to the stern tube flanges and aligned within

0.1mm. The aft seal liners could not be aligned due them being spigot fit and having a tight clearance to the shaft. The TIR was checked for informational purposes only.

MKII Seals Final Alignment

Port FWD. Seal .09mm

Port AFT Seal .09mm

STBD FWD. Seal .20mm

STBD AFT Seal .18mm

O. D. Boxes

Both Port and STBD O.D. boxes were completely disassembled, cleaned, and inspected.

No damage to either O.D. Box was present. Careful attention was made during the assembly process to ensure all parts were protected from any foreign debris that may cause a mechanical failure. Each box was re-assembled and installed onto the ship using new shafts, seals, and O-rings.

Operational Testing

Both Port and STBD CPP systems were operated using A&B pumps. Both propellers were cycled from Full Ahead to Full Astern several times to vent the air inside the system. Both

Hubs traveled smoothly throughout the entire pitch range. No binding or shuttering was observed during this process. No leaks were observed during the test either at the hub or inside the vessel at the O.D. Box.

Final wear down readings were taken and witnessed by the Port Engineer and the Chief

Engineer. They were recorded in the vessels wear down gauge chart.

Port Top: 64.50mm STBD Top: 66.60mm

Port Bottom: 65.55mm STBD Bottom: 66.20mm

Recommendations

1. New liners were provided during this availability. However, they were generic and were not machined to except the shafts or the spigot at the hub. Due to machinist availability and time constraints the decision was made to re-use the old liners. During the next overhaul the new FWD. and AFT liners will need to be machined to fit the Kings

Pointer application.

2. DMS recommends that MARAD reach out to an engineering company to perform a full shaft alignment and analysis on the Port side due to the current tail shaft to gearbox misalignment.

3. DMS recommends that MARAD reach out to Waukesha Bearing Corp. to perform a detailed bearing inspection and analysis.

4. DMS recommends hiring a controls technician to conduct calibration and grooming of both Port and STBD CPP systems.