heavy things (incl. mooring line) can pass through the bottom

[dankelley]

See below.

# issue: the line can pass through the bottom
library(mooring)
#> Loading required package: S7
par(mfrow = c(1, 3))
w <- wire(length = 50)
a <- anchor()
a@height <- 0
f <- float()
f@height <- 0
for (buoyancy in c(-300, -310, -320)) {
    i <- instrument(model = "fake", buoyancy = buoyancy, height = 0, area = 0.2, CD = 1)
    m <- mooring(a, w, i, w, f, waterDepth = 100)
    mk <- knockdown(segmentize(m), u = 1)
    plot(mk)
}

summary(m)
#> Mooring in 100m of water that has 5 elements, listed from the top down:
#>   1: "Kiel SFS40in" float, buoyancy 320kg, height 0m, area 0.785398m^2
#>   2: "1/4in wire/jack" wire, buoyancy -6.5kg, length 50m, area 0.4m^2
#>   3: "fake" instrument, buoyancy -320kg, height 0m, area 0.2m^2
#>   4: "1/4in wire/jack" wire, buoyancy -6.5kg, length 50m, area 0.4m^2
#>   5: "1 Railway Wheel" FIXME anchor, buoyancy -350kg, height 0m

^{Created on 2024-06-11 with reprex v2.1.0}