Table 12
Ontonagon Harbor Piers
Ontonagon, Michigan
Construction and Rehabilitation History
Date
Construction of the inner 1,069 ft of the west pier (Figures 28
1868-
and 29, Section E) occurred during this time. This structure con-
1872
sisted of woodpiling filled with stone. The pier width ranged from
8.5 to 1 1 ft.
The outer 1,515 ft of the east pier (Figures 28 and 29, Section A )
1868-
was built during this period. This was a rock-filled timber crib
1879
structure. The pier was 20 ft wide and had stone toe protection at
its base.
Construction of 1,398 ft of the west pier (Figures 28 and 29, Sec-
1875-
tion A) progressed. The pier had the same cross section as the pier
1890
built during 1868-79.
Construction of an additional 255 ft of the east pier (Figures 28
1881-
and 29, Section
was completed. This was a 20-ft-wide stone-filled
1882
timber crib structure with stone toe protection.
The inner 545 ft of the east pier (Figures 28 and 29, Section
was
1882-
built. This pier also was a stone-filled timber crib structure with
1888
a 20-ft crest width.
A stone superstructure was built on 1,515 and 1,398 ft of the east
1920-
and west piers, respectively (Figure 29, Section A).
The el of these
1935
piers was
ft lwd.
A concrete cap (superstructure) was constructed on the inner 1,069 ft
1933
of the west pier (Figure 29, Section E.
)
The el of the channel side
ft lwd.
of the pier was
A stone and concrete cap (superstructure) was installed on 800 ft of
1935-
1936
structure had a crest el of
ft lwd (Section C ) , while the remain-
ft lwd (Section B.
)
ing pier had an el of
The 96-ft-long west pierhead was rebuilt with steel sheetpiling that
1947
was stone filled. It was capped with 5-ton minimum cover stone. The
pierhead was 22 ft wide with a crest el of
ft lwd. Riprap was in-
stalled to provide toe protection. It is not clear when the pierhead
was originally constructed.
A structural inspection of the piers was made.
A void up to 20 ft
1983
wide was observed on the west pier, and sand was being lost through
the cribbing under the superstructure. Additional stone was required
(Continued)
55
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