What are you all talking about? Entry role for Elec or Mech Engineer in either design or manufacturing starts at £25k minimum (not sure about research and development). Realistically you will get £28-32k straight out of Uni on almost any 2-year graduate programme. Working 37.5h/week with little overtime (unless you ask for it, which will be compensated). +Benefits.
Having enough experience (3-5 years) you choose whether to excel in technology (lead engineering, senior engineering) or go into engineering management or engineering project/program management. At this stage you can expect anything between £42k up to £60k, depending on responsibilities and your impact. Again, 37.5h/week, however taking on greater responsibilities can sometimes mean working early/late or weekends - and yes, compensated!
I worked with both Technology departments (design engineering) and within manufacturing for a few years and have yet to experience any real pressure. I saw maybe 1-2 crysis situations a year max, but again, somethings is not right with the company itself (not the career) if you experience pressure all the time.
I enjoy my work (and the pay of course). Have energy after work and enjoy coming back to work every morning.
Having said that, every company is different, so choose wisely.