Union sizes

#pragma hdrstop
#include <stdio.h>
#include <conio.h>

union TUnion
{
     struct
     {
         unsigned char b1, b2, b3;
     };
     struct
     {
         unsigned short w1;
     };
} TUnion;

struct TDavidsRecord
{
    union TUnion u;
    unsigned char b4;
};

union TOriginalUnion
{
    struct
    {
        unsigned char b1, b2, b3;
    };
    struct
    {
        unsigned short w1;
    };
};


int main(int argc, char *argv[])
{
    printf("sizeof(TDavidsRecord)  = %d\n", sizeof(struct TDavidsRecord));
    printf("sizeof(TOriginalUnion) = %d\n", sizeof(union TOriginalUnion));
    getch();
    return 0;
}