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Support for Fin Whale Skulls


This storage system is designed to provide support for large finner type baleen whales. The system permits researchers relatively unhindered access to the skulls while minimizing the space needed to store these large objects.

This system could be adapted to store other large, bulky items that despite their size are fragile and require a secure frame for support.

In order to conserve space, these cradles are designed to store the skulls in an upright position (i.e. on the occipital condyles with the rostrum pointed upward). The skull cradle can be moved in either the upright mode or lowered so that the skull is lying with its ventral aspect up.
(Fig. 1).

Figure 1. Metal support cradles with fin whale skulls in vertical and horizontal positions.


Charles Potter
Dept. of Vertebrate Zoology
National Mus. of Natural History
Smithsonian Institution
Washington, DC 20560 USA
Tel (202) 786-2497
Fax (202) 357-1896

John Heyning
Natural History Museum
of Los Angeles County
900 Exposition Blvd.
Los Angeles, CA 90007 USA
Tel (213) 744-3414

Photographs: Charles Potter

Illustrations: David W. von Endt

Publication: 1992


The system consists of cradles reminiscent of boat trailers. The cradle frames are constructed of welded channel steel (or aluminum). The supporting elements are also channel steel but are adjustable via regularly spaced bolt holes and bolts. The size of the channel steel and lumber used for construction is dependent on the weight and size of the specimen.

For a large finback whale skull, Balaenoptera physalus, a frame was constructed out of 4in and 5in channel. This specimen was approximately 18ft long, 12ft wide, 41/2ft deep and weighed approximately 1500lbs. The cradle should be built slightly larger than the skull on each dimension so that no portion of the specimen overhangs the cradle.

Materials Tools Supplies

  • Casters, high-quality, 360 degree swivel with locking mechanisms, 8 for large specimens, 7 for smaller
  • Glue gun and hot melt adhesive or contact cement
  • Lag screws
  • Lumber, 2in x 4in and 2in x 6in, size and length depend on size of specimen
  • Nuts and bolts
  • Nylon webbing, 1-2in wide
  • Polyethylene foam, closed-cell
  • Polyethylene foam plank, 2in thick for smaller specimens, 4in thick for larger specimens
  • Polyethylene sheeting
  • Steel framing or aluminum framing with regularly spaced bolt holes, size and length depend on size of specimen to be housed


  1. Design and fabricate the support structure from steel or aluminum framing (Figs. 2, 3).

    Figure 2. Metal support frame. left, Side view showing detail of metal, wood, and foam pads. right, Front view.

    Figure 3. Metal support frame, top view 
    of end that supports the occipital condyles.
  2. Attach casters at locations indicated in the figures. The casters should be of high quality and have ball bearings in the axle, as well as in the swivel raceways. The tread should be of polytetrafluoroethylene, neoprene or some similar material that will not develop and “remember” flat spots due to sitting in one position for long periods of time. All casters should swivel a full 360 degrees and be equipped with locking mechanisms.
  3. Cushion contact points between the cradle and the skull with polyethylene foam pads mounted on either 2in x 4in pieces of wood (rostrum area) and 2in x 6in pieces of wood (base of the skull) or stiff polyethylene foam planking of similar dimensions.
  4. Insert the wooden supports into the channel frame and fasten with lag screws (Fig. 2, detail). Alternatively, cut polyethylene foam plank pieces the same size as the inside dimension of the channel and wedge them tightly into place.
  5. Attach polyethylene foam to the wooden supports with hot melt adhesive, contact cement or nylon webbing.
  6. Fasten the skull to the cradle with nylon webbing and strapping/banding tools (Fig. 4). By using nylon webbing, the skull is attached with a flexible, somewhat elastic medium.

    Figure 4. Nylon webbing straps are used to hold the specimen to the frame. 
    Pad contact points with the skull with polyethylene foam plank covered with 
    polyethylene sheeting or with closed-cell polyethylene foam, to reduce abrasion.


With the exception of the support elements, all the other metal elements are welded together. The support elements need to be adjustable and therefore should be bolted in place (Figs. 2, 3). The exact nature of the welds as well as the material used in the construction of the supports will depend on the size and weight of the specimen. For help in designing and constructing the frame, consult a metal fabricator.

Crucial to the success of this application is that the casters be of high quality to allow the individual specimen and cradle to be moved by one person. Using poor quality casters will defeat one of the primary purposes of this system: that the specimen be easily manipulated by one person by hand.

Because metal wheels transmit vibrations to the frame and specimen, due to irregularities in the floor (expansion joints, debris, etc.), they should not be used. Pneumatic wheels should be avoided as the tires have a tendency to dry rot as well as to develop leaks.

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