journey是单数,所以后面用was哦；
travel是复数名词,travels是指“旅行笔记”,所以只能用journey哦.
感觉一下,是不是听a journey 或者a trip舒服,而很少听到有人说a travel,a travel就成了一次游记,而不是一次旅行了.
如果一定要用travel,原句就变成了：Our travel from London to Istanbul by train were very tiring.原句的was就变成了were了.
journey通常指短途的一次旅行,而travel是指长途的断续的要换车或者露宿有停顿有间歇的旅行,所以是复数.
再给你举个例子：way 和means 都是方式的意思.The way to do this is simple,
The means of doing this are simple.