At common law the obligation to load, stow and discharge the cargo rests solely on the shipowner, but due to the fact that the loading is a particular operation in which both parties have to concur, the shipowner’s duty does not begin until the goods are under his charge.
Per Earl of Selborne LC, giving the leading judgement in Grant & Co v Coverdale, Todd & Co (1884) 9 App Cas 470 at 475-476:
This exception in the contract being limited to "accidents preventing the loading," the only question is, what is the meaning of "loading"? and whether this particular frost did, in fact, prevent the loading. There are two things to be done – the operation of loading is the particular operation in which both parties have to concur. Taken literally it is spoken of in the early part of this charterparty as the thing which the shipowner is to do. The ship is to "proceed to Cardiff East Bute Dock, and there load the cargo." No doubt, for the purpose of loading, the charterer must also do his part; he must have the cargo there to be loaded, and tender it to be put on board the ship in the usual and proper manner.
Therefore the business of both parties meets and concurs in that operation of loading. When the charterer has tendered the cargo, and when the operation has proceeded to the point at which the shipowner is to take charge of it, everything after that is the shipowner’s business, and everything before the commencement of the operation of loading, those things which are so essential to the operation of loading that they are conditions sine quibus non of that operation – everything before that is the charterer’s part only. It would appear to me to be unreasonable to suppose, unless the words make it perfectly clear, that the shipowner has contracted that his ship may be detained for an unlimited time on account of impediments, whatever their nature may be, to those things with which he has nothing whatever to do, which precede altogether the whole operation of loading, which are no part whatever of it, but which belong to that which is exclusively the charterer’s business. He has to contract for the cargo, he has to buy the cargo, he has to convey the cargo to the place of loading and have it ready there to be put on board; and it is only when he has done those things that the duty and the obligation of the shipowner in respect of the loading arises. These words in the exception are as large as any words can be; they mention "strikes, frosts, floods, and all other unavoidable accidents preventing the loading." If therefore you are to carry back the loading to anything necessary to be done by the charterer in order to have the cargo ready to be loaded, no human being can tell where you are to stop. The bankruptcy, for instance, of the person with whom he has contracted for the supply of the iron, or disputes about the fulfilment of the contract, the refusal at a critical point of time to supply the iron, the neglect of the persons who ought to put it on board lighters to come down the canal for any distance or to be brought by sea, or to put it on the railway or bring it in any other way in which it is to be brought; all those things are of course practical impediments to the charterer having the cargo ready to be shipped at the proper place and time; but is it reasonable that the shipowner should be held to be answerable for all those things, and is that within the natural meaning of the word "loading"? Are those things any part of the operation of loading? Nothing, I suppose, is better established in law with regard to mercantile cases of this kind than the maxim, "Causa proxima, non remota, spectatur"; and it appears to me that the fact that this particular wharf was very near the Cardiff East Bute Dock can make no difference in principle if it was not the place of loading. If the cargo had to be brought from this wharf on the Glamorganshire Canal, however near it was, if it had to be brought over a passage which in point of fact was impeded, and over which it was not brought, to the place of loading, to say that the wharf on the Glamorganshire Canal was, upon a fair construction of the words, within the place of loading, appears to me to be no more tenable than if the same thing had been said of a place a mile higher up the canal where, according to the actual contract, the persons were to supply the iron, and where the owner of the iron might be found.