Hours passed on the Kazakh side as H.P. and its shipping agents hustled to amend the paperwork, which was not easy because the error was discovered at the end of a workday. After thundering across China, through Xi’an, across a corner of the Gobi Desert and skirting the vast arid wastes of the Taklamakan Desert, where temperatures can hit 120 degrees, the train simply sat. For 26 hours.

Such extreme delays are unusual — H.P. managers say the longest previous delay was 10 hours, at the Belarus-Poland border. Sea shipments have sometimes been delayed up to three days because of bad weather and other problems.

H.P. has made strenuous efforts to keep the products moving, sending representatives to remote Central Asian border crossings to explain its plans, said Ronald Kleijwegt, the company’s director of logistics for Europe, the Mideast and Africa.

H.P. helped China overhaul its software for processing customs documents. China’s previous system allowed clerks to choose only an adjacent country in Asia as the final destination for rail shipments, Mr. Kleijwegt said, because no one had envisioned that exports in sealed rail cars might be sent nearly 7,000 miles to destinations in Europe.

The company also negotiated special customs clearance, permitting its containers to stay locked and uninspected at border crossings along the route, although the containers are X-rayed for contraband. That was mostly to shorten the time needed for the trip, but also for security. Two years ago, H.P. sent 200 computers in a single, unsealed container as a test shipment on a general-purpose freight train. The shipment went through comprehensive customs checks at border crossings. By the time the train reached Germany, many of the computers had disappeared.

‘Much Respect on the Track’

Once the problem of the transposed numbers was cleared up, the train crossed into Kazakhstan. An overhead crane and two cranes that looked like cottages on wheels lifted the H.P. containers off the Chinese train, and loaded them onto flat cars with wider wheel gauges in the rail yard in Dostyk on the Kazakh side of the border. Kazakhstan, Russia and Belarus, all traversed on the trip, have wide rails inherited from the Soviet rail system. China and Europe have narrower rails, so cargo transfers take several hours.

Mr. Kulyenov, a freight train driver fourth class who dreams of being promoted someday to reach the rank of passenger train driver first class, considered himself lucky to be driving the train. Sitting in the cab of a new diesel locomotive, he waited in the Dostyk rail yard for a messenger in a bright yellow safety jacket to bring him a computer printout of his cargo. When the printout arrived, he carefully made notations in the locomotive’s purple velvet-bound log book, a concession to tradition, then typed many of the same weight details into a dashboard computer that helps precisely calibrate the engine for pulling each load.