Swivel – Cargo, 6000 lb. Capacity

NFES Number: 
000286
Category: 
Aviation
Updated: 
2017-05
Storage and Shelf Life Checks: 
None

 

Cargo Swivel, 3000 lb. capacity.

Initial Inspection/Disposal Criteria

  1. Inspect swivel for rotation: Swivel shall rotate freely by hand (no binding) with no load. If swivel does not rotate freely, remove from service. If binding is suspected, perform the following free rotation test. Using a string, hang a 2 lb. weight to the hook. Close the hook and rotate the swivel slowly in one direction and then the other. The speed of rotation shall not be greater than 1 revolution in 5 seconds. If the binding of the swivel results in the string being carried around the rotation, remove the swivel from service.
Figure 1. Free Rotation Test with 2 lb. Weight
 
Line art of swivel rotation sideviewline art of top view of swivel rotation

 

  1. Inspect for excessive lateral movement of the swivel. Excessive lateral movement is defined as 5 degrees (angular measurement) of total movement and may indicate bearing wear. Remove from service.

 

Figure 2. Excessive Lateral Movement
Detail of excessive swivel movement.

 

  1. Inspect hook and linkage for damage, wear, and deformation:
    1. Inspect swivel rotating body or hook for any cracks or gouges. If cracks or gouges are found, remove from service.
    2. Inspect gate for type. If the gate is a spring gate (the hook opens by pushing the gate into the hook) it is an old style hook and needs replacement. Remove the swivel from service and refer to NFES Cache Memorandum
      No. 04-03, Cargo Swivel Retrofit Project dated 8/10/04: http://www.nifc.gov/nicc/logistics/cachememo/cm_NFES-cargo_08-10-04.pdf
    3. Inspect the swivel for the dimensions shown in Figure 3 and Table 1. If dimensions exceed those in Table 1, remove the swivel from service.
    4. Inspect the hook for the dimensions shown in Figure 4 and Table 2. If dimensions exceed those in Table 2, remove the swivel from service.
    5. Check the hook for damage such as cracks, nicks, wear, gouges, and deformation. Check operation and ensure that hook is not bent or distorted. If any damage is found, then remove from service.

 

               Figure 3. Swivel Dimensions                                               Figure 4. Shank Hook
Image of swivel dimensions on left, shank hook on right.

 

Table 1. Swivel dimensions
StyleCD
3000 pounds3 to 5 inch max5/8 inch nominal
6000 pounds 3 to 5 inch max5/8 inch nominal

 

Table 2. Shank Hook Dimensions
StyleA (max)B (max)
3000 pounds1.0 inch1.33 inch
6000 pounds1.3 inch1.7 inch

 

  1. Check the hook’s locking gate operation.
    • Ensure safety latch open and close completely.
    • Examine latch for damage or distortion.
    • Examine lock latch for rounded lock shoulder, see Figure 5
    • Ensure spring loaded latch hold the latch in the closed position.
    • Ensure lock latch pin is secure and flush with the latch, see Figure 5. If latch is damaged, does not operate as required, is missing hardware, or does not meet dimensional requirements remove from service.

 

Figure 5. Examine Gate Lock Latch for rounding.
 
image showing Gate Lock Latch inspection for rounding

Line art showing detail of where to look for Gate Lock Latch rounding.

Check for rounding of lock shoulder here

 

  1. Inspect the link and link fastener.
    • Check for damage such as cracks, nicks, wear, and gouges.
    • Check link for deformations. The curved ends of the link (either oblong or pear) should be generally circular in shape. If overstressing has occurred, the end portions of the link will appear “pinched.”  Figure 6 shows the pinched effect of overstressed parts.
    • If the link is attached to the swivel with a threaded fastener with nut:
      • Ensure that no more than 2 threads are exposed.
      • Ensure that the fastener has not slipped by inspecting the paint indication. Paint lines that line up indicate no slippage,see Figure 7. If slippage is indicated, refurbish as necessary or dispose of item.
      • Inspect the fastener and nut for damage (cracks and gouges).
        • If the link is attached with a pin secured with roll pins, ensure that the roll pins are not bent or cracked.
        • If damage is observed, refurbish as necessary or dispose of item.

Figure 6. Normal and "pinched" link shapes.
 
Normal link.Pinched link.Normal pear link.Pinched pear link.
NormalPinchedNormalPinched

 


Figure 7. Slippage paint indication.

Picture of bolts showing slippage paint indication.

 

  1. Return to stock if swivel is in sealed packaging and showing signs of usage.
  2. Refurbish if swivel has been removed from packaging, is in a used condition, or if deficiencies have been identified in inspection.
  3. Dispose of swivel if it fails Initial Inspection or Testing for Performance and repairs are not economical feasible to complete.

 

Refurbishing Procedure

A. Cleaning

  1. Wipe clean. Paint as needed.

B. Repair

Never repair, alter, rework, or reshape a hook, link, or swivel. Return to the manufacturer or qualified rigging company for repair.

  1. Swivel rotation binding and lateral movement repairs. These repairs shall be performed by the manufacturer or certified/qualified rigging facility. The typical repair is the replacement of the bearing.  If the bearing is replaced, the replacement bearing shall be capable of a bearing load 3.75 times the swivel’s rated capacity.
  2. Hook and link problems. The hooks and links of a swivel shall not be altered, rework, or reshaped.  They may be replaced.  Replacement components shall have a strength capacity of 3.75 times the load carrying capacity of the swivel. Return the swivel to the manufacturer or certified rigging facility for all replacement parts or repairs.
  3. Repaint the fastener slip indicator when necessary.  Paint as shown in Figure 7.
  4. All above repaired swivels (including replaced components) shall be tested per Testing for Performance.
  5. Link retaining fastener: Threaded link retaining fasteners that use a bolt and self-locking nut may be retightened in accordance with the Table 3: Link Fastener Torque Values. Paint fasteners as shown in Figure 7. Other fastener systems shall be sent to the manufacturer to be repair.

Table 3. Link Fastener Torque Values
Fastener SizeTorque (Ft-lbs.)
5/1612
3/820
7/1625
1/230

 

C. Testing for performance

  1. Repairs must be performed and tested by the manufacturer or certified/qualified rigging facility.
  2. Each and every repaired swivel shall be strength tested to 2.0 times its rated capacity. The swivel shall be placed into a tensile style loading device that has a current calibration. The swivel shall be tensile loaded to 2.0 times the rated capacity of the swivel. The swivel shall not show any signs of damage due to loading.
  3. Each and every swivel whose bearing is repaired shall pass the following tests:
    1. Free rotation. Open the hook. Rotate the swivel until the ‘jaw’ of the hook is down. Rotate the swivel slowly in one direction and then the other. The speed of rotation shall not be greater than 1 revolution in 5 seconds. The jaw should be held (due to gravity) to an orientation less than 135 degrees from vertical, see Figure 8. If the binding of the swivel results in the jaw of the hook rotating over the top the repair is unacceptable.
    2. The lateral movement test described in Initial Inspection/Disposal Criteria #2, except that maximum lateral movement shall be less than 2 degrees, see Figure 2.

Figure 8. Free Totation, Unloaded.
 
swivel show from top and the 135 degree rotation.Swivel with latch in open position.

 

  1. All replacement hardware (links, bearings, hooks) shall have a working load limit equal or greater than the working load limit of the corresponding swivel; and have a minimum ultimate strength equal to 11,250 pounds for 3000-lb capacity swivels and 22,500 pounds for 6,000-lb capacity swivels. Links and hooks shall meet the requirements of USDA Forest Service Specification for Swivel, 5100-506 for 6,000-lb swivels and 5100-501a for 3,000-lb swivels.
  2. For replaced shank style hooks, the threading of the hook shall follow the hook manufacturer’s recommendations.

D. Repackaging

  1. NFES #000526 package 6 each in NFES #008018 carton (12” x 12” x 6”).
  2. NFES #000286 package local cache option.

 

Page Last Modified / Reviewed: 
2019-02-26