Frame rail assemblies and interlocking frame rail systems

1. A frame rail assembly for a boat dock structure, the frame rail assembly comprising:

a frame rail member including a first side configured for securing the frame rail member to a side of the boat dock structure; a second side opposing the first side; a first channel extending along a length of the frame rail member; and a second channel below the first channel, the second channel extending along the length of the frame rail member; and

a first removable resilient rub-rail member projecting outward from the second side and extending along at least a portion of the length of the frame rail member, the first rub-rail member including a first coupling member having a cross-section shaped complementarily to a cross-section of the first channel and extending through the first channel in engagement therewith, and a second coupling member having a cross-section shaped complementarily to a cross-section of the second channel and extending through the second channel in engagement therewith, wherein the first rub-rail member includes an outer bumper shell projecting outward from the second side, and an inner rib disposed inside the outer bumper shell but not attached to the outer bumper shell, and configured for supporting the outer bumper shell upon heavy impact, the inner rib being oriented so as to be less deformable than the outer bumper shell;

wherein the cross-sections of the first coupling member and the second coupling member are sized and shaped such that the first coupling member and the second coupling member are limited to longitudinal insertion into and removal from the first channel and the second channel, respectively.

2. The frame rail assembly of claim 1 , wherein the outer bumper shell includes at least one raised ridge for improved traction.

3. The frame rail assembly of claim 1 , wherein the first channel includes an inner section and an outer section, the inner section having a larger cross-sectional area than the outer section; and the second channel includes an inner section and an outer section, the inner section having a larger cross-sectional area than the outer section.

4. The frame rail assembly of claim 1 , wherein the frame rail member includes an upper section through which the first channel extends, and a lower section, and further comprising:

a third channel in the lower section of the frame rail member extending along the length of the frame rail member;

a fourth channel above the third channel, the fourth channel extending along the length of the frame rail member; and

a second removable resilient rub-rail member projecting outward from the second side and extending along at least a portion of the length of the frame rail member, the second rub-rail member including a third coupling member extending through the third channel in engagement therewith, and a fourth coupling member extending through the fourth channel in engagement therewith.

5. The frame rail assembly of claim 4 , wherein the first and second rub-rail members include respective outer bumper shells projecting outward from the second side, and respective inner ribs disposed inside the outer bumper shells configured for supporting the respective outer bumper shells upon heavy impact, the respective inner ribs being oriented so as to be less deformable than the respective outer bumper shells.

6. The frame rail assembly of claim 4 , wherein:

the first channel includes an inner section and an outer section, the inner section having a larger cross-sectional area than the outer section, and the second channel includes an inner section and an outer section, the inner section having a larger cross-sectional area than the outer section, the first coupling member has a cross-section shaped complementarily to the first channel; the second coupling member has a cross-section shaped complementarily to the second channel; and the first channel and the second channel are configured such that the first rub-rail member is limited to longitudinal removal; and

the third channel includes an inner section and an outer section, the inner section having a larger cross-sectional area than the outer section, and the fourth channel includes an inner section and an outer section, the inner section having a larger cross-sectional area than the outer section, the third coupling member has a cross-section shaped complementarily to the third channel; the fourth coupling member has a cross-section shaped complementarily to the fourth channel; and the third channel and the fourth channel are configured such that the second rub-rail member is limited to longitudinal removal.

7. The frame rail assembly of claim 1 , wherein the cross-section of the first coupling member is substantially the same in area as the cross-section of the first channel and the cross-section of the second coupling member is substantially the same in area as the cross-section of the second channel.