Gantt

library(tidyverse)
library(lubridate)
library(readxl)
library(highcharter) # current github version (not release version)

Import Excel

df <- readxl::read_xlsx("BECS Safe Project.xlsx") %>%
  dplyr::mutate(
    Start = as.Date(Start),
    Finish = as.Date(Finish),
    Duration = as.numeric(strsplit(Duration, "d")), # strip away 'd'
    `Task ID` = as.character(`Task ID`),
    Predecessors = gsub(" ", "", Predecessors, fixed = TRUE) # strip whitespace
  ) %>%
  dplyr::mutate(
    dependency = strsplit(Predecessors, ",") # convert to vector
  ) %>%
  dplyr::mutate_if(is.Date, datetime_to_timestamp) %>%
  dplyr::rename(
    start = Start,
    end = Finish,
    name = `Task Name`,
    id = `Task ID`
  ) %>%
  dplyr::select(
    start, end, name, id, dependency
  )

Plot

highchart(type = "gantt") %>% 
  hc_size(width = NULL, height = 1500) %>%
  hc_exporting(
    enabled = TRUE, # always enabled
    filename = "custom-file-name"
    ) %>%
  hc_add_series(
    name = "Program",
    data = df
  ) %>% 
  hc_rangeSelector(enabled = TRUE) %>% 
  hc_navigator(
    enabled = TRUE,
    series = list(
      type = 'gantt',
      pointPlacement = 0.5,
      pointPadding =  0.25
    ),
    yAxis = list(
      min = 0,
      max = 52,
      reversed = TRUE,
      categories = c()
    )
  )