There are basically three types of pontoons that come into question for floating objects: those made of reinforced concrete, steel, or "fiberglass".
The following is an analysis of these pontoons, in terms of their static load-bearing capacity, draft, and maintenance. The main role, however, is played by the weight of the pontoon, since this governs the potential capacity of the building. This analysis also focused on other uses, such as integrated sewage treatment, head pump etc..
ANALYSIS:
A) Reinforced Concrete
Dimensions: Width:6 m, Length:20 m, Height:1.50 m, Wall thickness: 0.18 m
Design: The reinforced concrete body is of smooth monolithic construction prepared in a form, with a structure comprising 18 cm thick walls of dual-reinforced impervious concrete. No protective coat is required on the inside or outside.
Static load-bearing capacity: The reinforced concrete alone bears the load, eliminating the need for supplementary bracing elements like frames or bulkheads. Portions of concrete pontoons have a foam core to ensure the pontoon is unsinkable even if fissures develop, or in case of continuous water intake. Materials used for foam cores are not always harmless.
Displacement: 6 m width x 20 m length x 1 m draft = 120 m³ of displaced water
120 m³ x 1000 = 120,000 kg maximum weight
120,000 kg = 120 t
This means that a floating home with a draft of 1 m should not weigh more than 120 t, including the pontoon. N.B.: The weight of the building and pontoon should be specified separately, since the decisive factor is the structure above, not the pontoon.
Weight of reinforced concrete pontoon: 6.00 m x 20.00 m x 1.50 m = 180 m³. 180 m³ - 5.64 m x 19.64 m x 1.32 m = 33.78 m³
Total weight of pontoon: 33.78 m³ x 2.5 t/m³ = 84.45 tLoad capacity of building: 120 t - 84.45 t = 35.55 t
Hence, taking working loads etc. into account, the maximum permissible weight of the complete building structure including all built-in units is 35.55 t.
Ice stability: The manufacturer warrants the unit's ice stability.
Maintenance: The pontoon is basically maintenance-free, and is backed by a 20 year warranty against water ingress.
Other uses: The pontoon has no added walls or bracing elements, and can thus serve as a basement or sewage treatment unit.
Disadvantages: Unsafe Styrofoam core; no thermal insulation; buildup of condensation; permanent deformation; brittle, hence danger of developing fissures
B) Steel Pontoon
Dimensions: Width:6 m, Length:20 m, Height:1.50 m. Wall thickness: 0.01 m
Design: As in shipbuilding, the vessel is made of welded steel plates with frames and bulkheads. The wall structure comprises 1 cm thick steel plates. A protective coat is required either inside or outside.
Static load-bearing capacity: Extra frames and bulkheads are required as bracing elements.
Displacement: 6 m width x 20 m length x 1 m draft = 120 m³ of displaced water 120 m³ x 1000 = 120,000 kg maximum weight, 120,000 kg = 120 t
This means that a floating home with a draft of 1 m should not weigh more than 120 t, including the pontoon.
Weight of steel pontoon: 6.00 m x 20.00 m x 1.50 m = 180 m³. 180 m³ - 5.98m x 19.98 m x 1.49 m = 2.57 m³. 2.57 m³ x 7.85 t/m³ = 20.2 t
Transverse bulkheads: 0.01 m x 1.00 m x 5.98 m x 4 = 0.24 m³. 0.24 m³ x 7.85 t/m³ = 1.88 t
Longitudinal bulkhead: 0.01 m x 1.00 m x 19.98 = 0.20 m³. 0.20 m³ x 7.85 t/m³ = 1.57 t
Frames according to marine navigation regulations:. 0.01 m x 1.00 m x 0.25 m x 90 = 0.23 m³. 0.23 m ³ x 7.85 t/m³ = 1.81 t
Frames on the pontoon floor: 0.01 m x 0.25 m x 5.98 m x 35 = 0.52 m³. 0.52 m³ x 7.85 t/m³ = 4.08 t
Total weight of pontoon: 20.2 t + 1.88 t + 1.57 t + 1.81 t + 4.08 t = 29.54 t
Load capacity of building:120 t - 29.54 t = 90.46 t
Hence, taking working loads etc. into account, the maximum permissible weight of the complete building structure including all built-in units is 91.32 t.
Ice stability: mIce stability must be verified by the manufacturer. Additional structures may be required.
Maintenance: The pontoon is not maintenance-free, and must be serviced once a decade. It is important to have a maintenance schedule, since access to the homes via bridges must be assured in places like Hamburg, Germany.
Other uses: Because of its bulkheads, the pontoon could be used simultaneously for sewage treatment, gray water storage, or partially as a basement.
Disadvantages: No thermal insulation; buildup of condensation; if water collects in the bilge, pontoon's life will be under 10 years; harmful antirust paint, and permanent deformations.
C) Studio Noach Fiberglass Pontoons
Dimensions:Width:6 m, Length:20 m, Height:1.50 m, Wall thickness: 0.044 m
Design: These pontoons are composites made of laminated plates bonded with epoxy and cured. The wall structure comprises 4.4 cm thick GraniteResin plates.
Static load-bearing capacity: Extra frames, bulkheads, or columns are required as bracing elements.
Displacement: 6 m width x 20 m length x 1 m draft = 120 m³ of displaced water120 m³ x 1000 = 120,000 kg maximum weight, 120,000 kg = 120 t
This means that a floating home with a draft of 1 m should not weigh more than 120 t, including the pontoon.
Weight of fiberglass pontoon: 6.00 m x 20.00 m x 1.50 m = 180 m³. 180 m³ - 5.91 m x 19.91 m x 1.41 m = 152.77 m³. 14.09 m³ x 0.23 t/m³ = 3.24 t
Transverse bulkheads: 0.044 m x 1.00 m x 5.91 m x 4 = 1.04 m³. 1.04 m³ x 0.23 t/m³ = 0.24 t
Longitudinal bulkhead: 0.044 m x 1.00 m x 19.91 = 0.88 m³. 0.88 m³ x 0.23 t/m³ = 0.20 t
Frames according to marine navigation regulations: 55 cm per Germanischer Lloyd. 0.044 m x 1.00 m x 0.50 m x 90 = 1.98 m³. 1.98 m ³ x 0.23 t/m³ = 0.46 t
Frames under the pontoon: 0.044 m x 0.10 m x 5.50 m x 35 = 0.85 m³. 0.85 m³ x 0.23 t/m³ = 0.20 to
Total weight of pontoon: 3.24 t + 0.24 t + 0.20 t + 0.46 t + 0.20 t = 4.34 tLoad capacity of building: 120 t - 4.34 t = 115.66 t
Hence, taking working loads etc. into account, the maximum permissible weight of the complete building structure including all built-in units is 115.66 t.
Ice stability: The manufacturer warrants the unit's ice stability.
