SOW Strain Gage Alignment Inspection.doc

24310_FJL_0826_615

STATEMENT OF WORK: Propulsion Shafting, Strain Gauge Alignment, Dockside, Check

1. SCOPE

1.1 Intent. This work item describes the requirements for the Contractor to perform strain gauge alignment inspection of the Port and Starboard Main Reduction Gear (MRG) bearing loads onboard Coast Guard Cutter RELIANCE (WMEC 615) while the cutter is moored pierside.

1.2 Government-furnished property.

None.

2. REFERENCES

Coast Guard Drawings

Coast Guard Drawing 618 WMEC 244-004, Rev A, Shafting Alignment (RELIANCE) Coast Guard Publications

None Other References

None

3. REQUIREMENTS

3.1 Alignment survey personnel. The Contractor must provide the services of an Alignment Engineer who is an expert in propulsion shafting alignment using strain gauge method to measure loading on Main Reduction Gear internal bearings.

3.2 Definitions and standard units. For the purposes of this specification and any reports generated, the following definitions apply.

3.2.1 Optimal alignment. Defined as a state of shaft alignment (through all phases of bearing wear down) where:

· Bearing loads are within a satisfactory range

· Bending stresses are minimal

· Gear box bearing loads (Fwd and Aft) always remain positive and are near equal at midlife wear

· Shaft slope through long bearings matches the bearing slope within a reasonable range

· Horizontal loads are minimized

NOTE

“Optimal alignment” is the goal when components are being moved or relocated e.g. foundations altered, chockfast poured, new strut being installed, new stern tube installed, etc.

3.2.2 Acceptable alignment. Defined as a state of achievable shaft alignment where components are constrained (movement/relocations not within work scope) but:

· Current bearing loads are within a satisfactory range and if possible remain satisfactory though continued bearing wear down

· Horizontal loads are minimized Note

“Acceptable alignment” is the goal whenever “Optimal alignment” cannot be achieved because the scope of associated work does not provide for relocation of components necessary.

3.2.3 Standard units. All reports, correspondences, and discussions must be in Standard/US Customary Units and not in SI/Metric Units.

3.3 Strain gauge alignment check. The Contractor must perform the specified actions in Table 1 below using Coast Guard Drawing 618 WMEC 244-004 as guidance.

Table 1 - Tasks

3.3.1.1

3.3.1.2

3.3.2

3.3.3

3.3.1.1

3.3.1.2

3.3.2

3.3.3

3.3.1 Shaft alignment check by strain gage method. The Contractor must furnish all necessary equipment and install sufficient strain gages, measure strains, and calculate vertical and horizontal reactions using the strain gage measurement method. Perform the strain gage measurements under the direct supervision of personnel experienced in and regularly engaged in shaft alignment by the strain gage method.

3.3.1.1 Install strain gages internally to measure all internal bearing reactions.

3.3.1.2 All strain gages must remain at the same locations throughout all required inspections. Do not duplicate cost of installation if strain gauges are already installed from previous evolutions.

3.3.2 Strain gauge report. The Contractor must submit a written report of results via CFR with the following information to the COR within 24 hours after alignment check:

· All specified (i.e. external and/or internal) bearing reactions

· Deviation from specified bearing reactions in Coast Guard Drawing 618 WMEC 244-001 or 618 WMEC 244-004 as applicable

· A description of the alignment procedures used to obtain the bearing loads

· Strain gauge locations

· All mathematics values used in the shaft model such as material properties, spring constant, thermal growth effects, bearing offsets, all concentrated weights, etc

· All assumptions applied in the shaft model

· All constant values used in the shaft model

· Any indication of misalignment

· Any recommended corrective procedures. The recommended corrective procedures must include, but not be limited to:

· New bearing off-sets to achieve an Optimal alignment (as defined in 3.2.1)

· Other alternative to achieve an Optimal alignment

· Detailed procedures to achieve shaft alignment

· Table of calculated bearing wear down analysis based on prior strain gauge reports (furnished upon request by COR)

4. NOTES

4.1 Results submittal. The COR will forward a copy of each strain gauge report to the MECPL Engineering Branch.

4.2 Alignment check prerequisites, afloat. Ship’s Force will ensure the following conditions are met for the afloat alignment check:

· All shaft components are installed.

· Vessel is in the water for at least 24 hours before alignment inspection.

· All permanent ballast are in place.

· Fuel, water, and temporary ballast tanks are filled to normal operating levels, generally half to 75% capacity.

· Vessel is on an even keel.

· All major machinery weighing over 500 pounds is either installed or simulated by equivalent weights appropriately located

· The shafts must be free to rotate and the stern tube face seal shall not be any tighter than necessary note

Small boats are not considered major machinery and therefore do not need to be simulated by equivalent weights in their absence.

4.3 Period of Performance.

Primary: 21 September to 9 October 2026

Secondary: 28 September to 16 October 2026

Tertiary: 2 November to 20 November 2026

4.4 Place of Performance. The primary place of performance will be CGC RELIANCE located at below address:

211 South Avenue

Pensacola, Fl 32508

4.3 Point of Contact. LT Megan Wadleigh, Engineering Officer (EO). Megan.A.Wadleigh@uscg.mil