Liverpool Street will be difficult with all your baggage, but at least it's all going to be on one level, so I don't think Liverpool Street is going to be your main problem.

Your main problems will be getting to the ferry from Amsterdam (unless someone is taking you there by car), and getting off the ferry and onto the train at Harwich.

There is no ferry from Amsterdam to Harwich. Your ferry is from Hoek van Holland, about 90 minutes from Amsterdam by train with a change at Rotterdam Centraal. The train station in Hoek van Holland is next to the ferry terminal, but it's quite a long walk to the ferry.

On the ferry you'll have to make your way to your cabin (which could be quite a long walk, along very narrow corridors), and I don't think they have porters to assist you.

Then, on arrival at Harwich, you've got another walk, and I can't remember if there are lifts (elevators) there.

The Harwich to Liverpool Street train, although it's a direct service that connects with the ferry, is a commuter train with very little baggage space... and if you're travelling on the overnight ferry, and it's a weekday, your train will get progressively more packed because - unlike in the old days of dedicated non-stop "boat trains" - it's just an ordinary train and it will be full of people travelling to work. (If you're on the day boat this won't apply as not a lot of people travel from Harwich to London in the evening).

Do you really have to take all that baggage just for a week? Isn't there somewhere you can leave it in Amsterdam?

Is 18 days. but yes i will think i can leave something in AMS but i will have 3 big bags + the kids and gear. I cannot pack any lighter than that.

Some people are suckers for punishment.

With a baggage train such as that envisaged by the OP I would have a long, hard think about my itinerary and logistics before buying a single ticket.

Sheesh, he is supposed to be enjoying himself, not preparing for an eternity in Purgatory!

Could you not get it down to 2 suitcases? plus the 2 carry on type bags? or go for a bigger rucksack (the hiking type so about the equivalent size of a suitcase) then that would be on your back leaving both hands free for the two suitcases

NVM im droping the ship, 200 euro to the trash, and getting a plane. My destination is covent garden, should i go to LHR or LCY?

Thanks guys!

Did you think about arranging for a large taxi to meet you and the family at Harwich?

If you're contemplating flying into LHR or LCY, you still face the challenge of getting from the airport to Covent Garden ... for which I'd recommend that you arrange to be met by a large taxi.

Large taxi to Hook of holland is arround 200e from AMS, and same from Hartwich to london, so 400e. Now i spend 200 dollars + 6750 avios. And maybe a little more in some taxi but it seems more normal travel and faster for all

I'd definitely take a taxi or hire a car between airport (regardless of whether its lhr or lcy) and covent garden, even with two adults if you have a large amount of luggage plus two children, with double stroller etc then i wouldn't both trying to use the train/tube at all, indeed with the tube they're quite fussy if they think you've got more luggage than you can easily handle about letting you on at all :/

Thanks! yes Taxi will be the transportation method. I will have london-paris train but that is much much easy than the whole ferry craziness.

If you are going to fly, do bear in mind that BA have a limit of 1 bag of 23kg per person, including children, unless you have have one world status.

LCY is a far easier airport to handle than LHR - getting through is a breeze.

[edit] Ah, now I'm no longer on the mobile phone, I see you have OneWorld status. So it'll be 2 bags/person with a 32kg limit.

FWIW, there is a direct connection between LHR and Covent Garden on the Piccadilly Line.

Moreoever, both stations are step-free.

I haven't been through Covent Garden station in a while, but that doesn't sound right. Just checked Wikipedia which says there's a flight of steps between lift and exit. If memory serves me it's just a few steps. But the difference between step-free and a few steps can be a big deal when you're as encumbered as the OP says he will be.

Issue solved. Flew from AMS to LCY, take a regular black taxi, it cost 30 pounds and took me to the hotel. Thanks guys for helping, i think i would be in a very bad mood if i took the train then ferry then train again then taxi

There are elevators from near platform level to the street exit.

Only trams and the likes, and possibly Heathrow Express. I haven't seen any other UK railway station with no step up at all (and I've seen many) - but as noted, it's not usually a big step, I'd guess about 4 to 8", not flights of stairs as found in mainland Europe and the US.

Clapham Junction platform 17, on the other hand, is scary; the (horizontal) gap between train and platform is almost a foot.

Neil